Application: systemsettings5 (5.2.2)
 (Compiled from sources)
Qt Version: 5.4.1
Operating System: Linux 3.19.0-22-generic x86_64
Distribution: Ubuntu 15.04

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

everytime I click on 'workspace Theme' in the systeme settings, the app crashes.
It only crashes with this one.

The crash can be reproduced every time.

-- Backtrace:
Application: System Settings (systemsettings5), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fbb1168a780 (LWP 21188))]

Thread 3 (Thread 0x7fbafeeb3700 (LWP 21189)):
#0  0x00007fbb0ddec8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fbb0c106b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fbb0c10864f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fbb01c46099 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so
#4  0x00007fbb0e46db0e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fbb0b0206aa in start_thread (arg=0x7fbafeeb3700) at pthread_create.c:333
#6  0x00007fbb0ddf7eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fbaeff8d700 (LWP 21190)):
#0  0x00007fbb0ddec8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fbb0ab01ebc in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fbb0ab01fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fbb0e704c6c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fbb0e6a93e2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fbb0e468b44 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fbb0d433f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007fbb0e46db0e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fbb0b0206aa in start_thread (arg=0x7fbaeff8d700) at pthread_create.c:333
#9  0x00007fbb0ddf7eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fbb1168a780 (LWP 21188)):
[KCrash Handler]
#6  0x00007fbb0dd26267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#7  0x00007fbb0dd27eca in __GI_abort () at abort.c:89
#8  0x00007fbb0e45aedf in QMessageLogger::fatal(char const*, ...) const () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007fbb0cedb791 in QSGRenderLoop::handleContextCreationFailure(QQuickWindow*, bool) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#10 0x00007fbb0cee506f in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007fbb0cee530a in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#12 0x00007fbb0eee37b5 in QWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#13 0x00007fbb0cf16dd3 in QQuickWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#14 0x00007fbb0f497b2c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007fbb0f49d000 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#16 0x00007fbb0e6abc2b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007fbb0eedbe86 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#18 0x00007fbb0eedcbbd in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#19 0x00007fbb0eec134f in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#20 0x00007fbb01c70590 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so
#21 0x00007fbb0ab01c3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007fbb0ab01f20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#23 0x00007fbb0ab01fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007fbb0e704c57 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00007fbb0e6a93e2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007fbb0e6b102c in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x000000000040eebc in main ()

Reported using DrKonqi