Application: systemsettings5 (5.2.95)
 (Compiled from sources)
Qt Version: 5.4.1
Operating System: Linux 3.19.2-031902-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed:
I was applying changes to the effect of the desktop.. this happens often

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 0x7f2c49be0780 (LWP 4072))]

Thread 4 (Thread 0x7f2c374bc700 (LWP 4073)):
#0  0x00007f2c4634e8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f2c44668b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f2c4466a64f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f2c3a27a099 in QXcbEventReader::run (this=0x1e00270) at qxcbconnection.cpp:1105
#4  0x00007f2c469cfb0e in QThreadPrivate::start (arg=0x1e00270) at thread/qthread_unix.cpp:337
#5  0x00007f2c435826aa in start_thread (arg=0x7f2c374bc700) at pthread_create.c:333
#6  0x00007f2c46359eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f2c1d5d6700 (LWP 4083)):
#0  0x00007f2c430a8789 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f2c43063dbd in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f2c43063fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f2c46c66c6c in QEventDispatcherGlib::processEvents (this=0x7f2c040008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#4  0x00007f2c46c0b3e2 in QEventLoop::exec (this=this@entry=0x7f2c1d5d5e40, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f2c469cab44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007f2c469cfb0e in QThreadPrivate::start (arg=0x22318d0) at thread/qthread_unix.cpp:337
#7  0x00007f2c435826aa in start_thread (arg=0x7f2c1d5d6700) at pthread_create.c:333
#8  0x00007f2c46359eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f2c1fded700 (LWP 4119)):
#0  0x00007f2c4634e8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f2c43063ebc in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f2c43064242 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f2c08f5bae6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007f2c4308a955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f2c435826aa in start_thread (arg=0x7f2c1fded700) at pthread_create.c:333
#6  0x00007f2c46359eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f2c49be0780 (LWP 4072)):
[KCrash Handler]
#6  0x00007f2c45457d7e in QQuickItemPrivate::addToDirtyList() () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007f2c45457e28 in QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f2c45462045 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007f2c46c3f73a in QObject::event (this=0x2df2ff0, e=<optimized out>) at kernel/qobject.cpp:1245
#10 0x00007f2c45460b6b in QQuickItem::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007f2c479f9b2c in QApplicationPrivate::notify_helper (this=0x1dd3430, receiver=0x2df2ff0, e=0x7f2c0022c5a0) at kernel/qapplication.cpp:3720
#12 0x00007f2c479ff000 in QApplication::notify (this=0x7ffc3bd70f50, receiver=0x2df2ff0, e=0x7f2c0022c5a0) at kernel/qapplication.cpp:3503
#13 0x00007f2c46c0dc2b in QCoreApplication::notifyInternal (this=0x7ffc3bd70f50, receiver=0x2df2ff0, event=event@entry=0x7f2c0022c5a0) at kernel/qcoreapplication.cpp:935
#14 0x00007f2c46c0fc9b in sendEvent (event=0x7f2c0022c5a0, 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=0x1dd2650) at kernel/qcoreapplication.cpp:1552
#16 0x00007f2c46c10298 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#17 0x00007f2c46c66843 in postEventSourceDispatch (s=0x1e3e0c0) at kernel/qeventdispatcher_glib.cpp:271
#18 0x00007f2c43063c3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f2c43063f20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f2c43063fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f2c46c66c57 in QEventDispatcherGlib::processEvents (this=0x1e474b0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007f2c46c0b3e2 in QEventLoop::exec (this=this@entry=0x7ffc3bd70e30, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007f2c46c1302c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#24 0x000000000040ef5b in main ()

Reported using DrKonqi