Application: plasmashell (5.9.2)

Qt Version: 5.8.0
Frameworks Version: 5.31.0
Operating System: Linux 4.4.48-1-MANJARO x86_64
Distribution: "Manjaro Linux"

-- Information about the crash:
- What I was doing when the application crashed:

1. Login to newly upgraded Plasma 5 Desktop.
2. Click on the Widget Icon on the Desktop (Top left icon with 3 horizontal lines) to create new Activity.

Expected Behavior: 
Pop menu should display with option to create new activity

Actual Behavior: 
Plasma Shell crashed and restarted with heavy CPU usage by systemd-coresump process. After 1 - 2 minutes desktop is usable with CPU usage dropped to normal level.

Workaround to avoid this Crash: 
Right Click on Desktop and select unlock widgets.
Now click on widget icon. Plasmashell does not crash.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f5c9cd9c800 (LWP 883))]

Thread 7 (Thread 0x7f5be8808700 (LWP 981)):
#0  0x00007f5c96b308a9 in QMutex::lock() () at /usr/lib/libQt5Core.so.5
#1  0x00007f5c96d687df in  () at /usr/lib/libQt5Core.so.5
#2  0x00007f5c91262c89 in g_main_context_prepare () at /usr/lib/libglib-2.0.so.0
#3  0x00007f5c912636ab in  () at /usr/lib/libglib-2.0.so.0
#4  0x00007f5c9126389c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#5  0x00007f5c96d6906b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007f5c96d1289a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#7  0x00007f5c96b34a73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#8  0x00007f5c9a821fd6 in  () at /usr/lib/libQt5Quick.so.5
#9  0x00007f5c96b396d8 in  () at /usr/lib/libQt5Core.so.5
#10 0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#11 0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7f5c6efb8700 (LWP 980)):
#0  0x00007f5c95a0a10f in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f5c9c516234 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f5c9c516279 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f5c7cd60700 (LWP 979)):
#0  0x00007f5c96d68992 in  () at /usr/lib/libQt5Core.so.5
#1  0x00007f5c91263179 in g_main_context_check () at /usr/lib/libglib-2.0.so.0
#2  0x00007f5c91263724 in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007f5c9126389c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007f5c96d6906b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007f5c96d1289a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007f5c96b34a73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#7  0x00007f5c99c6e025 in  () at /usr/lib/libQt5Qml.so.5
#8  0x00007f5c96b396d8 in  () at /usr/lib/libQt5Core.so.5
#9  0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f5c7e7c0700 (LWP 973)):
#0  0x00007fff8f7efc79 in clock_gettime ()
#1  0x00007f5c9645b6b6 in clock_gettime () at /usr/lib/libc.so.6
#2  0x00007f5c96d68201 in  () at /usr/lib/libQt5Core.so.5
#3  0x00007f5c96d669c9 in QTimerInfoList::updateCurrentTime() () at /usr/lib/libQt5Core.so.5
#4  0x00007f5c96d66f75 in QTimerInfoList::timerWait(timespec&) () at /usr/lib/libQt5Core.so.5
#5  0x00007f5c96d6863e in  () at /usr/lib/libQt5Core.so.5
#6  0x00007f5c91262c89 in g_main_context_prepare () at /usr/lib/libglib-2.0.so.0
#7  0x00007f5c912636ab in  () at /usr/lib/libglib-2.0.so.0
#8  0x00007f5c9126389c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#9  0x00007f5c96d6906b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#10 0x00007f5c96d1289a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#11 0x00007f5c96b34a73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#12 0x00007f5c99c6e025 in  () at /usr/lib/libQt5Qml.so.5
#13 0x00007f5c96b396d8 in  () at /usr/lib/libQt5Core.so.5
#14 0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#15 0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f5c7ffff700 (LWP 912)):
#0  0x00007fff8f7efc79 in clock_gettime ()
#1  0x00007f5c9645b6b6 in clock_gettime () at /usr/lib/libc.so.6
#2  0x00007f5c96d68201 in  () at /usr/lib/libQt5Core.so.5
#3  0x00007f5c96d669c9 in QTimerInfoList::updateCurrentTime() () at /usr/lib/libQt5Core.so.5
#4  0x00007f5c96d66f75 in QTimerInfoList::timerWait(timespec&) () at /usr/lib/libQt5Core.so.5
#5  0x00007f5c96d6863e in  () at /usr/lib/libQt5Core.so.5
#6  0x00007f5c91262c89 in g_main_context_prepare () at /usr/lib/libglib-2.0.so.0
#7  0x00007f5c912636ab in  () at /usr/lib/libglib-2.0.so.0
#8  0x00007f5c9126389c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#9  0x00007f5c96d6906b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#10 0x00007f5c96d1289a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#11 0x00007f5c96b34a73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#12 0x00007f5c9717e125 in  () at /usr/lib/libQt5DBus.so.5
#13 0x00007f5c96b396d8 in  () at /usr/lib/libQt5Core.so.5
#14 0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#15 0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f5c86021700 (LWP 894)):
#0  0x00007f5c9644548d in poll () at /usr/lib/libc.so.6
#1  0x00007f5c9b43c8e0 in  () at /usr/lib/libxcb.so.1
#2  0x00007f5c9b43e679 in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007f5c87f60239 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f5c96b396d8 in  () at /usr/lib/libQt5Core.so.5
#5  0x00007f5c95a04454 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007f5c9644e7df in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f5c9cd9c800 (LWP 883)):
[KCrash Handler]
#6  0x00007f5c9a8ccde1 in QQuickItemPrivate::setEffectiveVisibleRecur(bool) () at /usr/lib/libQt5Quick.so.5
#7  0x00007f5c9a8ccdea in QQuickItemPrivate::setEffectiveVisibleRecur(bool) () at /usr/lib/libQt5Quick.so.5
#8  0x00007f5c9a8ccf44 in QQuickItem::setVisible(bool) () at /usr/lib/libQt5Quick.so.5
#9  0x00007f5c9c84a08c in  () at /usr/lib/libKF5PlasmaQuick.so.5
#10 0x00007f5c9c84b8c6 in PlasmaQuick::Dialog::event(QEvent*) () at /usr/lib/libKF5PlasmaQuick.so.5
#11 0x00007f5c97c8234c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#12 0x00007f5c97c89b61 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#13 0x00007f5c96d14440 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#14 0x00007f5c974f778e in QWindow::setVisible(bool) () at /usr/lib/libQt5Gui.so.5
#15 0x00007f5c9c84797c in PlasmaQuick::Dialog::setVisible(bool) () at /usr/lib/libKF5PlasmaQuick.so.5
#16 0x00007f5c9c84a818 in  () at /usr/lib/libKF5PlasmaQuick.so.5
#17 0x00007f5c9c84c07b in PlasmaQuick::Dialog::qt_metacall(QMetaObject::Call, int, void**) () at /usr/lib/libKF5PlasmaQuick.so.5
#18 0x00007f5c99be1ac9 in  () at /usr/lib/libQt5Qml.so.5
#19 0x00007f5c99be0498 in QQmlPropertyPrivate::write(QObject*, QQmlPropertyData const&, QVariant const&, QQmlContextData*, QFlags<QQmlPropertyData::WriteFlag>) () at /usr/lib/libQt5Qml.so.5
#20 0x00007f5c99baab7b in QV4::QObjectWrapper::setProperty(QV4::ExecutionEngine*, QObject*, QQmlPropertyData*, QV4::Value const&) () at /usr/lib/libQt5Qml.so.5
#21 0x00007f5c99bab390 in QV4::QObjectWrapper::setQmlProperty(QV4::ExecutionEngine*, QQmlContextData*, QObject*, QV4::String*, QV4::QObjectWrapper::RevisionMode, QV4::Value const&) () at /usr/lib/libQt5Qml.so.5
#22 0x00007f5c99bab4a6 in QV4::QObjectWrapper::put(QV4::Managed*, QV4::String*, QV4::Value const&) () at /usr/lib/libQt5Qml.so.5
#23 0x00007f5c99bbbf56 in QV4::Runtime::method_setProperty(QV4::ExecutionEngine*, QV4::Value const&, int, QV4::Value const&) () at /usr/lib/libQt5Qml.so.5
#24 0x00007f5be936cf42 in  ()
#25 0x000000000273ef40 in  ()
#26 0x00007f5be936d504 in  ()
#27 0x00007f5c6f801408 in  ()
#28 0x0003400000000001 in  ()
#29 0x00000000000004fa in  ()
#30 0x0003400000000000 in  ()
#31 0x00007fff8f7e9930 in  ()
#32 0x0000000000000000 in  ()

Reported using DrKonqi