Application: systemsettings5 (5.2.2)
 (Compiled from sources)
Qt Version: 5.4.1
Operating System: Linux 3.19.0-15-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
I was tried to change windows the windows style and ever that I click on the system pref / windows style this app close and giv me a error message

The crash can be reproduced sometimes.

-- Backtrace:
Application: Preferencias del sistema (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7efc90c56780 (LWP 8012))]

Thread 5 (Thread 0x7efc7e2df700 (LWP 8013)):
#0  0x00007efc8d3b98dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007efc8b6d3b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007efc8b6d564f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007efc81072099 in QXcbEventReader::run (this=0x1efb260) at qxcbconnection.cpp:1105
#4  0x00007efc8da3ab0e in QThreadPrivate::start (arg=0x1efb260) at thread/qthread_unix.cpp:337
#5  0x00007efc8a5ed6aa in start_thread (arg=0x7efc7e2df700) at pthread_create.c:333
#6  0x00007efc8d3c4eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7efc6f032700 (LWP 8015)):
#0  0x00007efc8d3b98dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007efc8a0ceebc in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007efc8a0cefcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007efc8dcd1c6c in QEventDispatcherGlib::processEvents (this=0x7efc680008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#4  0x00007efc8dc763e2 in QEventLoop::exec (this=this@entry=0x7efc6f031e20, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007efc8da35b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007efc8ca00f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007efc8da3ab0e in QThreadPrivate::start (arg=0x2130930) at thread/qthread_unix.cpp:337
#8  0x00007efc8a5ed6aa in start_thread (arg=0x7efc6f032700) at pthread_create.c:333
#9  0x00007efc8d3c4eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7efc676c5700 (LWP 8016)):
#0  0x00007fff211fbc58 in clock_gettime ()
#1  0x00007efc8d3d338d in __GI___clock_gettime (clock_id=<optimized out>, tp=<optimized out>) at ../sysdeps/unix/clock_gettime.c:115
#2  0x00007efc8daf0cb6 in qt_clock_gettime (ts=0x7efc676c4b80, clock=<optimized out>) at tools/qelapsedtimer_unix.cpp:105
#3  do_gettime (frac=<synthetic pointer>, sec=<synthetic pointer>) at tools/qelapsedtimer_unix.cpp:161
#4  qt_gettime () at tools/qelapsedtimer_unix.cpp:170
#5  0x00007efc8dccf639 in QTimerInfoList::updateCurrentTime (this=this@entry=0x7efc60002cd0) at kernel/qtimerinfo_unix.cpp:84
#6  0x00007efc8dccfba5 in QTimerInfoList::timerWait (this=0x7efc60002cd0, tm=...) at kernel/qtimerinfo_unix.cpp:379
#7  0x00007efc8dcd103e in timerSourcePrepareHelper (timeout=0x7efc676c4c54, src=<optimized out>) at kernel/qeventdispatcher_glib.cpp:127
#8  timerSourcePrepare (source=<optimized out>, timeout=0x7efc676c4c54) at kernel/qeventdispatcher_glib.cpp:160
#9  0x00007efc8a0ce3fd in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007efc8a0cede8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007efc8a0cefcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007efc8dcd1c6c in QEventDispatcherGlib::processEvents (this=0x7efc600008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#13 0x00007efc8dc763e2 in QEventLoop::exec (this=this@entry=0x7efc676c4e20, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#14 0x00007efc8da35b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#15 0x00007efc8ca00f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#16 0x00007efc8da3ab0e in QThreadPrivate::start (arg=0x28434d0) at thread/qthread_unix.cpp:337
#17 0x00007efc8a5ed6aa in start_thread (arg=0x7efc676c5700) at pthread_create.c:333
#18 0x00007efc8d3c4eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7efc65007700 (LWP 8017)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007efc8da3bc6b in wait (time=18446744073709551615, this=0x279ffd0) at thread/qwaitcondition_unix.cpp:128
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x2815cd0, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:200
#3  0x00007efc8c4acfab in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007efc8c4ad3a0 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007efc8da3ab0e in QThreadPrivate::start (arg=0x2815c50) at thread/qthread_unix.cpp:337
#6  0x00007efc8a5ed6aa in start_thread (arg=0x7efc65007700) at pthread_create.c:333
#7  0x00007efc8d3c4eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7efc90c56780 (LWP 8012)):
[KCrash Handler]
#6  0x0000002b80000009 in ?? ()
#7  0x00007efc6f75e6e1 in KDecoration2::Decoration::update(QRect const&) () from /usr/lib/x86_64-linux-gnu/libkdecorations2.so.5
#8  0x00007efc6f75e75b in KDecoration2::Decoration::update() () from /usr/lib/x86_64-linux-gnu/libkdecorations2.so.5
#9  0x00007efc679b8370 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/breezedecoration.so
#10 0x00007efc679d87a8 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/breezedecoration.so
#11 0x00007efc8da1b5ca in updateProperty (newValue=..., this=0x280f7b0) at animation/qpropertyanimation.cpp:135
#12 QPropertyAnimation::updateCurrentValue (this=<optimized out>, value=...) at animation/qpropertyanimation.cpp:242
#13 0x00007efc8da16f48 in QVariantAnimationPrivate::setCurrentValueForProgress (this=this@entry=0x280f7b0, progress=progress@entry=0.96444444444444444) at animation/qvariantanimation.cpp:290
#14 0x00007efc8da17d1b in recalculateCurrentInterval (force=false, this=0x280f7b0) at animation/qvariantanimation.cpp:275
#15 QVariantAnimation::updateCurrentTime (this=<optimized out>) at animation/qvariantanimation.cpp:693
#16 0x00007efc8da13baf in QAbstractAnimation::setCurrentTime (this=0x2805b70, msecs=130) at animation/qabstractanimation.cpp:1321
#17 0x00007efc8da13e96 in updateAnimationsTime (delta=20, this=0x204c490) at animation/qabstractanimation.cpp:606
#18 QUnifiedTimer::updateAnimationTimers (this=0x2172fa0) at animation/qabstractanimation.cpp:323
#19 0x00007efc8da147dc in QAnimationDriver::advanceAnimation (this=<optimized out>, timeStep=-1) at animation/qabstractanimation.cpp:820
#20 0x00007efc8c4911ee in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#21 0x00007efc8c4af68a in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#22 0x00007efc8c4b1a8b in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#23 0x00007efc8c4b230a in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#24 0x00007efc8e4b07b5 in QWindow::event (this=0x2315430, ev=<optimized out>) at kernel/qwindow.cpp:2051
#25 0x00007efc8c4e3dd3 in QQuickWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#26 0x00007efc8ea64b2c in QApplicationPrivate::notify_helper (this=0x1ece4a0, receiver=0x2315430, e=0x7fff21188290) at kernel/qapplication.cpp:3720
#27 0x00007efc8ea6a000 in QApplication::notify (this=0x7fff21188690, receiver=0x2315430, e=0x7fff21188290) at kernel/qapplication.cpp:3503
#28 0x00007efc8dc78c2b in QCoreApplication::notifyInternal (this=0x7fff21188690, receiver=receiver@entry=0x2315430, event=event@entry=0x7fff21188290) at kernel/qcoreapplication.cpp:935
#29 0x00007efc8e4a8e86 in sendSpontaneousEvent (event=0x7fff21188290, receiver=0x2315430) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#30 QGuiApplicationPrivate::processExposeEvent (e=0x23522f0) at kernel/qguiapplication.cpp:2613
#31 0x00007efc8e4a9bbd in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x23522f0) at kernel/qguiapplication.cpp:1638
#32 0x00007efc8e48e34f in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:572
#33 0x00007efc8109c590 in userEventSourceDispatch (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#34 0x00007efc8a0cec3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#35 0x00007efc8a0cef20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#36 0x00007efc8a0cefcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#37 0x00007efc8dcd1c57 in QEventDispatcherGlib::processEvents (this=0x1f422d0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#38 0x00007efc8dc763e2 in QEventLoop::exec (this=this@entry=0x7fff21188570, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#39 0x00007efc8dc7e02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#40 0x00007efc8e49f31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#41 0x00007efc8ea607a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#42 0x000000000040eebc in main (argc=1, argv=<optimized out>) at ../../app/main.cpp:54

Reported using DrKonqi