Application: systemsettings5 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-15-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed : 
i was tryng different kde theme, change desktop wallpaper, just setting up my pc, i did a fresh install

The crash can be reproduced sometimes.

-- Backtrace:
Application: Impostazioni di sistema (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f031c227780 (LWP 3119))]

Thread 3 (Thread 0x7f0309b27700 (LWP 3120)):
#0  0x00007f031898e8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f0316ca8b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f0316caa64f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f030c8ba099 in QXcbEventReader::run (this=0x17121b0) at qxcbconnection.cpp:1105
#4  0x00007f031900fb0e in QThreadPrivate::start (arg=0x17121b0) at thread/qthread_unix.cpp:337
#5  0x00007f0315bc26aa in start_thread (arg=0x7f0309b27700) at pthread_create.c:333
#6  0x00007f0318999eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f02de7fc700 (LWP 3136)):
#0  0x00007f031898e8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f03156a3ebc in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f03156a4242 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f02efb6eae6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007f03156ca955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f0315bc26aa in start_thread (arg=0x7f02de7fc700) at pthread_create.c:333
#6  0x00007f0318999eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f031c227780 (LWP 3119)):
[KCrash Handler]
#6  0x00007f0317aabde0 in QQuickWindow::maybeUpdate() () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007f0317a97e28 in QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f0317aa2045 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007f031927f73a in QObject::event (this=0x241a6f0, e=<optimized out>) at kernel/qobject.cpp:1245
#10 0x00007f0317aa0b6b in QQuickItem::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007f031a039b2c in QApplicationPrivate::notify_helper (this=0x16e5430, receiver=0x241a6f0, e=0x7f02d00739a0) at kernel/qapplication.cpp:3720
#12 0x00007f031a03f000 in QApplication::notify (this=0x7fff6b0089b0, receiver=0x241a6f0, e=0x7f02d00739a0) at kernel/qapplication.cpp:3503
#13 0x00007f031924dc2b in QCoreApplication::notifyInternal (this=0x7fff6b0089b0, receiver=0x241a6f0, event=event@entry=0x7f02d00739a0) at kernel/qcoreapplication.cpp:935
#14 0x00007f031924fc9b in sendEvent (event=0x7f02d00739a0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#15 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x16e4650) at kernel/qcoreapplication.cpp:1552
#16 0x00007f0319250298 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#17 0x00007f03192a6843 in postEventSourceDispatch (s=0x175aa10) at kernel/qeventdispatcher_glib.cpp:271
#18 0x00007f03156a3c3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f03156a3f20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f03156a3fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f03192a6c57 in QEventDispatcherGlib::processEvents (this=0x1759a60, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007f031924b3e2 in QEventLoop::exec (this=this@entry=0x7fff6b008890, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007f031925302c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#24 0x00007f0319a7431c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#25 0x00007f031a0357a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#26 0x000000000040eebc in main (argc=1, argv=<optimized out>) at ../../app/main.cpp:54

Reported using DrKonqi