Bug 366190

Summary: KDE KickOff Application Launcher crashes when typing to search for applications
Product: [Plasma] plasmashell Reporter: Francisco Cribari <cribari>
Component: Application Launcher (Kickoff)Assignee: David Edmundson <kde>
Status: RESOLVED DUPLICATE    
Severity: normal CC: aspotashev, cribari, hr567q, plasma-bugs, rdieter, svetoslav80
Priority: NOR    
Version: 5.7.2   
Target Milestone: 1.0   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Francisco Cribari 2016-07-28 01:30:29 UTC
I recently migrated from Gnome to KDE. I am running KDE Plasma 5.7.2 on Arch Linux. I am having an annoying problem: The KDE KickOff application launcher sometimes crashes while I am typing to search for an application by its name. It first freezes, then the entire panel vanishes, then the panel returns to the desktop. I only have one widget. I removed it, but the problem did not go away. I have also disabled "Expand search to bookmarks, files and emails" under Application Launcher Settings. The problem persists. Removing the panel and creating a new one did not help either. I am using the standard Breeze theme. After struggling with this issue for a while, yesterday I changed the menu style to "Application Dashboard". My notebook has an Intel integrated graphics card and I am not using proprietary drivers. The only two desktop effects I activated were: (i) Desktop cube and (ii) Magic lamp. I disabled them and the crashes did not go away. This is what I have in Compositor (enabled on startup): Animation speed: medium, Scale method: Accurate, Rendering backend: OpenGL 2.0, OpenGL interface: GLX, Tearing prevention ("vsync"): Automatic, Keep window thumbnails: Only for Shown Windows.

Reproducible: Always

Hardware: Dell XPS 13, model 9343, Intel GPU.

Reproducible: Always

Steps to Reproduce:
Steps to Reproduce:
1. Select "Application Launcher" under KickOff -> Alternatives. 
2. Start the KickOff menu.
3. Type text to search for matching applications, 


Actual Results:  
Actual Results:  
Oftentimes (not always) the kickoff freezes and then the panel is restarted. 

Expected Results:  
Expected Results:  
We should be able to type text with no freezes or crashes. Matching applications should be displayed. 


Backtrace (via gdb): 

#0  0x0000000000000110 in ?? ()
#1  0x00007ffff1ee5e27 in QMetaObject::activate(QObject*, int, void**) () from /usr/lib/libQt5Core.so.5
#2  0x00007ffff4e1117f in ?? () from /usr/lib/libQt5Qml.so.5
#3  0x00007ffff506041a in QQmlDelegateModel::_q_itemsChanged(int, int, QVector<int> const&) ()
   from /usr/lib/libQt5Qml.so.5
#4  0x00007ffff5087a9c in ?? () from /usr/lib/libQt5Qml.so.5
#5  0x00007ffff50881d8 in QQmlDelegateModel::qt_metacall(QMetaObject::Call, int, void**) ()
   from /usr/lib/libQt5Qml.so.5
#6  0x00007ffff1ee5684 in QMetaObject::activate(QObject*, int, int, void**) ()
   from /usr/lib/libQt5Core.so.5
#7  0x00007ffff1f5ccbc in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () from /usr/lib/libQt5Core.so.5
#8  0x00007fff40ac21f0 in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#9  0x00007fff40abf59c in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#10 0x00007fff40ad30c9 in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#11 0x00007ffff1ee54e9 in QMetaObject::activate(QObject*, int, int, void**) ()
   from /usr/lib/libQt5Core.so.5
#12 0x00007fff38809682 in Plasma::RunnerManager::matchesChanged(QList<Plasma::QueryMatch> const&) ()
   from /usr/lib/libKF5Runner.so.5
#13 0x00007fff3880e6f0 in ?? () from /usr/lib/libKF5Runner.so.5
#14 0x00007ffff1ee54e9 in QMetaObject::activate(QObject*, int, int, void**) ()
   from /usr/lib/libQt5Core.so.5
#15 0x00007ffff1ef2568 in QTimer::timerEvent(QTimerEvent*) () from /usr/lib/libQt5Core.so.5
#16 0x00007ffff1ee6303 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#17 0x00007ffff2e24e3c in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
   from /usr/lib/libQt5Widgets.so.5
#18 0x00007ffff2e2c5b1 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#19 0x00007ffff1eb9c80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) ()
---Type <return> to continue, or q <return> to quit---
   from /usr/lib/libQt5Core.so.5
#20 0x00007ffff1f0d51e in QTimerInfoList::activateTimers() () from /usr/lib/libQt5Core.so.5
#21 0x00007ffff1f0da41 in ?? () from /usr/lib/libQt5Core.so.5
#22 0x00007fffec8a1dd7 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#23 0x00007fffec8a2040 in ?? () from /usr/lib/libglib-2.0.so.0
#24 0x00007fffec8a20ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#25 0x00007ffff1f0e57f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/libQt5Core.so.5
#26 0x00007ffff1eb80da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/libQt5Core.so.5
#27 0x00007ffff1ec05cc in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#28 0x000000000041b5fd in ?? ()
#29 0x00007ffff152b741 in __libc_start_main () from /usr/lib/libc.so.6
#30 0x000000000041b979 in _start ()
Comment 1 Francisco Cribari 2016-07-31 23:09:58 UTC
Is there any extra information I can provide?
Comment 2 Francisco Cribari 2016-08-02 18:35:42 UTC
The problem remains in Plasma 5.7.3.
Comment 3 Alexander Potashev 2016-08-25 21:46:16 UTC
This may have the same roots with https://bugs.kde.org/show_bug.cgi?id=342763
Comment 4 Francisco Cribari 2016-08-26 02:33:22 UTC
This is what I have installed: qt4 version 4.8.7-9 and qt5-base version 5.7.0-2 (Arch packages).
Comment 5 Francisco Cribari 2016-09-18 01:50:05 UTC
This video shows the Plasma crashes I am experiencing: https://www.youtube.com/watch?v=u-aGfU-whhA
Comment 6 Francisco Cribari 2016-09-20 02:31:48 UTC
Related bug: https://bugs.kde.org/show_bug.cgi?id=369092
Comment 7 David Edmundson 2016-09-20 16:36:12 UTC
Interestingly it's not a related bug. Same action, different cause.

This is the same bug as the infamous 342763 and 346118
which are completely different actions, with the same cause. There is a patch for Qt pending.
Comment 8 Francisco Cribari 2016-10-04 15:40:08 UTC
More backtrace info available at http://pastebin.com/8S2sMj1q
Comment 9 Rex Dieter 2016-10-04 15:58:21 UTC
Pasting in backtrace from comment #8 (though unfortunately it's missing debuginfo):

cribari@darwin4 ~ $ gdb plasmashell
GNU gdb (GDB) 7.11.1
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from plasmashell...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/bin/plasmashell 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[New Thread 0x7fffe151b700 (LWP 23845)]
[New Thread 0x7fffdb705700 (LWP 23846)]
[New Thread 0x7fffd9cbe700 (LWP 23847)]
[New Thread 0x7fffd3fff700 (LWP 23848)]
[New Thread 0x7fffd2397700 (LWP 23849)]
No metadata file in the package, expected it at: "/home/cribari/wallpaper/"
No metadata file in the package, expected it at: "/home/cribari/wallpaper/"
No metadata file in the package, expected it at: "/home/cribari/wallpaper/"
[New Thread 0x7fff42cf9700 (LWP 23850)]
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Panel.qml:80: TypeError: Cannot read property 'formFactor' of null
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/ToolTipDelegate.qml:41: TypeError: Cannot read property 'length' of undefined
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/ToolTipDelegate.qml:41: TypeError: Cannot read property 'length' of undefined
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/main.qml:106:20: Unable to assign [undefined] to int
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui/Task.qml:46:29: Unable to assign [undefined] to bool
file:///usr/share/plasma/plasmoids/org.kde.plasma.systemtray/contents/ui/main.qml:28: TypeError: Cannot read property 'Layout' of null
file:///usr/share/plasma/plasmoids/org.kde.plasma.systemtray/contents/ui/main.qml:29: TypeError: Cannot read property 'Layout' of null
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/Tooltip.qml:43: TypeError: Cannot read property 'timeFormat' of null
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Cannot anchor to a null item.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Could not resolve property : radialGradient4857
Could not resolve property : radialGradient4857
Could not resolve property : radialGradient4857
Could not resolve property : radialGradient4857
Containment id 57 that used to be a system tray was deleted
Notifications service registered
XSync seems available and ready
XSync Inited
Supported, init completed
[New Thread 0x7fff2c8d1700 (LWP 23851)]
libkcups: Create-Printer-Subscriptions last error: 0 successful-ok
libkcups: Get-Jobs last error: 0 successful-ok
libkcups: Get-Jobs last error: 0 successful-ok
Plasma Shell startup completed
libkcups: 0
libkcups: 0
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
networkmanager-qt: void NetworkManager::NetworkManagerPrivate::propertiesChanged(const QVariantMap&) Unhandled property "AllDevices"
networkmanager-qt: void NetworkManager::NetworkManagerPrivate::propertiesChanged(const QVariantMap&) Unhandled property "Devices"
networkmanager-qt: void NetworkManager::NetworkManagerPrivate::propertiesChanged(const QVariantMap&) Unhandled property "GlobalDnsConfiguration"
[New Thread 0x7fff1b0d9700 (LWP 23858)]
trying to show an empty dialog
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
[New Thread 0x7fff22e0a700 (LWP 23861)]
[New Thread 0x7fff22609700 (LWP 23862)]
[New Thread 0x7fff21e08700 (LWP 23863)]
[New Thread 0x7fff21607700 (LWP 23864)]
[New Thread 0x7fff20e06700 (LWP 23865)]
[New Thread 0x7fff20605700 (LWP 23866)]
[New Thread 0x7fff1a8d8700 (LWP 23867)]
[New Thread 0x7fff1a0d7700 (LWP 23868)]
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/KickoffItem.qml:188:9: QML Text: Binding loop detected for property "y"
file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/SearchView.qml:57:23: QML KickoffItem: Binding loop detected for property "height"

Thread 1 "plasmashell" received signal SIGSEGV, Segmentation fault.
0x00007ffff1ee2e25 in QMetaObject::activate(QObject*, int, void**) () from /usr/lib/libQt5Core.so.5
(gdb) bt
#0  0x00007ffff1ee2e25 in QMetaObject::activate(QObject*, int, void**) () from /usr/lib/libQt5Core.so.5
#1  0x00007ffff4e0f17f in ?? () from /usr/lib/libQt5Qml.so.5
#2  0x00007ffff505e41a in QQmlDelegateModel::_q_itemsChanged(int, int, QVector<int> const&) ()
   from /usr/lib/libQt5Qml.so.5
#3  0x00007ffff5085a9c in ?? () from /usr/lib/libQt5Qml.so.5
#4  0x00007ffff50861d8 in QQmlDelegateModel::qt_metacall(QMetaObject::Call, int, void**) ()
   from /usr/lib/libQt5Qml.so.5
#5  0x00007ffff1ee2684 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#6  0x00007ffff1f59cbc in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () from /usr/lib/libQt5Core.so.5
#7  0x00007fff374111c0 in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#8  0x00007fff3740e56c in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#9  0x00007fff37422099 in ?? () from /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#10 0x00007ffff1ee24e9 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#11 0x00007fff36f51602 in Plasma::RunnerManager::matchesChanged(QList<Plasma::QueryMatch> const&) ()
   from /usr/lib/libKF5Runner.so.5
#12 0x00007fff36f56670 in ?? () from /usr/lib/libKF5Runner.so.5
#13 0x00007ffff1ee24e9 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#14 0x00007ffff1eef568 in QTimer::timerEvent(QTimerEvent*) () from /usr/lib/libQt5Core.so.5
#15 0x00007ffff1ee3303 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#16 0x00007ffff2e21e3c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#17 0x00007ffff2e295b1 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#18 0x00007ffff1eb6c80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#19 0x00007ffff1f0a51e in QTimerInfoList::activateTimers() () from /usr/lib/libQt5Core.so.5
#20 0x00007ffff1f0aa41 in ?? () from /usr/lib/libQt5Core.so.5
#21 0x00007fffec8b5e67 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0x00007fffec8b60d0 in ?? () from /usr/lib/libglib-2.0.so.0
#23 0x00007fffec8b617c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
---Type <return> to continue, or q <return> to quit--- 
#24 0x00007ffff1f0b57f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/libQt5Core.so.5
#25 0x00007ffff1eb50da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#26 0x00007ffff1ebd5cc in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#27 0x000000000041b54d in ?? ()
#28 0x00007ffff152a291 in __libc_start_main () from /usr/lib/libc.so.6
#29 0x000000000041b8ca in _start ()
(gdb)
Comment 10 Francisco Cribari 2016-10-04 18:28:46 UTC
A Brazilian KDE maintainer  (Lamarque Souza) seems to be believe that the bug I reported is the same as this one, for which there is a patch: https://bugreports.qt.io/browse/QTBUG-53677 . The proposed patch: https://codereview.qt-project.org/#/c/160884/ .
Comment 11 Francisco Cribari 2016-10-10 15:19:10 UTC
I found a way for the KDE developers to reproduce this bug. Using the Application Launcher (not the Application Menu nor the Application Dashboard), go to the menu: -> Applications tab -> Internet. Then, find Chromium, right-click on its icon, select "Edit Application...", go to the Application tab and find the "Command" field. There we read 

chromium %U

append the following to that command: --force-device-scale-factor=1.1 . The command then becomes 

chromium %U --force-device-scale-factor=1.1 

Now, click on the Application Launcher menu and type to search fast. Type several names and backspace to return. For instance, type

displaycal followed by several backspaces
telegram followed by several backspaces
colord-kde followed by several backspaces
etc. 

At some point there will be a Plasma crash. See this video: https://www.youtube.com/watch?v=u-aGfU-whhA&t=2s
Comment 12 Francisco Cribari 2016-10-12 18:18:11 UTC
I created a new user, logged in as the new user and there were no crashes at all. After I modified the fonts in the System Settings the crashes started to take place. I am attaching below the backtrace info. 
*
BACKTRACE:
*
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fa2cb72f800 (LWP 15202))]

Thread 17 (Thread 0x7fa1e8ff9700 (LWP 15413)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#7  0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#8  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#9  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 16 (Thread 0x7fa1e97fa700 (LWP 15412)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#7  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#8  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#9  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#10 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#11 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#12 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#13 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#14 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#15 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#16 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#17 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#18 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#19 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#20 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#21 0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#22 0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#23 0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#24 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 15 (Thread 0x7fa1e9ffb700 (LWP 15411)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#7  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#8  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#9  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#10 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#11 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#12 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#13 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#14 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#15 0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#16 0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#17 0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#18 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 14 (Thread 0x7fa1ea7fc700 (LWP 15410)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 13 (Thread 0x7fa1eaffd700 (LWP 15409)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#7  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#8  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#9  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#10 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#11 0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#12 0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#13 0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#14 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 12 (Thread 0x7fa1eb7fe700 (LWP 15408)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 11 (Thread 0x7fa1ebfff700 (LWP 15407)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#7  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#8  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#9  0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#10 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#11 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#12 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#13 0x00007fa20c1759e2 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#14 0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#15 0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#16 0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#17 0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#18 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 10 (Thread 0x7fa1f0d90700 (LWP 15406)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cc2b in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa20c1711c0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#3  0x00007fa20c175988 in  () at /usr/lib/libKF5ThreadWeaver.so.5
#4  0x00007fa20c170263 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib/libKF5ThreadWeaver.so.5
#5  0x00007fa20c1731f9 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5
#6  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 9 (Thread 0x7fa1f7cb8700 (LWP 15405)):
#0  0x00007fa2c46514b8 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2c553cb66 in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/libQt5Core.so.5
#2  0x00007fa2c5538274 in  () at /usr/lib/libQt5Core.so.5
#3  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#4  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#5  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 8 (Thread 0x7fa206de0700 (LWP 15353)):
#0  0x00007fa2c4e4848d in poll () at /usr/lib/libc.so.6
#1  0x00007fa2c0111786 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fa2c576a72b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c55370f3 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fa20930c0a7 in KCupsConnection::run() () at /usr/lib/libkcupslib.so
#7  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 7 (Thread 0x7fa217100700 (LWP 15347)):
#0  0x00007fa2c010e7c9 in  () at /usr/lib/libglib-2.0.so.0
#1  0x00007fa2c01110b4 in g_main_context_check () at /usr/lib/libglib-2.0.so.0
#2  0x00007fa2c0111724 in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007fa2c576a72b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007fa2c55370f3 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#7  0x00007fa2c9438856 in  () at /usr/lib/libQt5Quick.so.5
#8  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#9  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7fa2a5b3e700 (LWP 15328)):
#0  0x00007fa2c465110f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fa2caec8ac4 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007fa2caec8b09 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7fa2a77a4700 (LWP 15299)):
#0  0x00007fa2c4e4848d in poll () at /usr/lib/libc.so.6
#1  0x00007fa2c0111786 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fa2c576a72b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c55370f3 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fa2c88992d5 in  () at /usr/lib/libQt5Qml.so.5
#7  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7fa2ad59e700 (LWP 15251)):
#0  0x00007fa2c4e4848d in poll () at /usr/lib/libc.so.6
#1  0x00007fa2c0111786 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fa2c576a72b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c55370f3 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fa2c88992d5 in  () at /usr/lib/libQt5Qml.so.5
#7  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7fa2aefe5700 (LWP 15223)):
#0  0x00007fa2c0110ecc in g_main_context_query () at /usr/lib/libglib-2.0.so.0
#1  0x00007fa2c01116f8 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fa2c576a72b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c55370f3 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fa2c62b7e55 in  () at /usr/lib/libQt5DBus.so.5
#7  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7fa2b4d73700 (LWP 15215)):
#0  0x00007fa2c4e4848d in poll () at /usr/lib/libc.so.6
#1  0x00007fa2c9e098e0 in  () at /usr/lib/libxcb.so.1
#2  0x00007fa2c9e0b679 in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007fa2b6ab0449 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007fa2c553bd78 in  () at /usr/lib/libQt5Core.so.5
#5  0x00007fa2c464b454 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007fa2c4e517df in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7fa2cb72f800 (LWP 15202)):
[KCrash Handler]
#5  0x00007fa2c5741f95 in QMetaObject::activate(QObject*, int, void**) () at /usr/lib/libQt5Core.so.5
#6  0x00007fa2c866e10f in  () at /usr/lib/libQt5Qml.so.5
#7  0x00007fa2c88bd2aa in QQmlDelegateModel::_q_itemsChanged(int, int, QVector<int> const&) () at /usr/lib/libQt5Qml.so.5
#8  0x00007fa2c88e492c in  () at /usr/lib/libQt5Qml.so.5
#9  0x00007fa2c88e5068 in QQmlDelegateModel::qt_metacall(QMetaObject::Call, int, void**) () at /usr/lib/libQt5Qml.so.5
#10 0x00007fa2c57417f4 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/libQt5Core.so.5
#11 0x00007fa2c57b8e4c in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () at /usr/lib/libQt5Core.so.5
#12 0x00007fa2150db3b0 in  () at /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#13 0x00007fa2150d875c in  () at /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#14 0x00007fa2150ec309 in  () at /usr/lib/qt/qml/org/kde/plasma/private/kicker/libkickerplugin.so
#15 0x00007fa2c5741659 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/libQt5Core.so.5
#16 0x00007fa214340602 in Plasma::RunnerManager::matchesChanged(QList<Plasma::QueryMatch> const&) () at /usr/lib/libKF5Runner.so.5
#17 0x00007fa214345670 in  () at /usr/lib/libKF5Runner.so.5
#18 0x00007fa2c5741659 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/libQt5Core.so.5
#19 0x00007fa2c574e6d8 in QTimer::timerEvent(QTimerEvent*) () at /usr/lib/libQt5Core.so.5
#20 0x00007fa2c5742473 in QObject::event(QEvent*) () at /usr/lib/libQt5Core.so.5
#21 0x00007fa2c6680e0c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#22 0x00007fa2c6688581 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#23 0x00007fa2c5715de0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#24 0x00007fa2c57696ae in QTimerInfoList::activateTimers() () at /usr/lib/libQt5Core.so.5
#25 0x00007fa2c5769bd1 in  () at /usr/lib/libQt5Core.so.5
#26 0x00007fa2c0111587 in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#27 0x00007fa2c01117f0 in  () at /usr/lib/libglib-2.0.so.0
#28 0x00007fa2c011189c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#29 0x00007fa2c576a70f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#30 0x00007fa2c571423a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#31 0x00007fa2c571c73c in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#32 0x000000000041c8b2 in  ()
#33 0x00007fa2c4d89291 in __libc_start_main () at /usr/lib/libc.so.6
#34 0x000000000041cc3a in _start ()
Comment 13 David Edmundson 2016-11-04 12:01:36 UTC
*** Bug 372052 has been marked as a duplicate of this bug. ***
Comment 14 Francisco Cribari 2016-11-04 13:40:55 UTC
I believe the bug is related to the fonts used. I have a high DPI screen, have the Google fonts installed (ttf-google-fonts) and use the infinality fonts bundle. Switching the system fonts (System Setting -> Font) from ABeeZee to Oxygen made the crashes go away.
Comment 15 Светослав Бацоев 2017-03-08 19:31:10 UTC
I'm experiencing a similar bug in 5.8.5. When I try to search, only the first typed letter appears in the search box, and it won't allow me to type any more letters. And then the launcher won't hide if I click outside it (but this only happens sometimes). Your suggestion to change the font size and dpi and the desktop theme won't work for me, unfortunately.
Comment 16 Светослав Бацоев 2017-03-08 19:37:24 UTC
Small Correction: The launcher will hide if I click outside it, but won't hide if I press Esc. This behavior only happens if I've tried to search for an app by typing in the launcher.
Comment 17 David Edmundson 2017-03-08 20:21:38 UTC

*** This bug has been marked as a duplicate of bug 369430 ***