Application: kwin_x11 (5.9.5)

Qt Version: 5.7.1
Frameworks Version: 5.34.0
Operating System: Linux 4.11.3-202.fc25.x86_64 x86_64
Distribution: "Fedora release 25 (Twenty Five)"

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

I deleted an VM in Virtual Machine Manager. Sometimes it crashes, sometimes not.

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fa3646bd940 (LWP 31092))]

Thread 5 (Thread 0x7fa32f7af700 (LWP 31149)):
#0  0x00007fa376657460 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fa37bf702f4 in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib64/libQt5Script.so.5
#2  0x00007fa37bf70339 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib64/libQt5Script.so.5
#3  0x00007fa37665173a in start_thread () from /lib64/libpthread.so.0
#4  0x00007fa373ac6e7f in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7fa33c968700 (LWP 31138)):
#0  0x00007fa373abb001 in ppoll () from /lib64/libc.so.6
#1  0x00007fa3748bd971 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () from /lib64/libQt5Core.so.5
#2  0x00007fa3748bee86 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#3  0x00007fa37487268a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#4  0x00007fa3746cf5e3 in QThread::exec() () from /lib64/libQt5Core.so.5
#5  0x00007fa37b1c54e5 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5
#6  0x00007fa3746d39ca in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5
#7  0x00007fa37665173a in start_thread () from /lib64/libpthread.so.0
#8  0x00007fa373ac6e7f in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fa354a56700 (LWP 31137)):
#0  0x00007fa373abb001 in ppoll () from /lib64/libc.so.6
#1  0x00007fa3748bd971 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () from /lib64/libQt5Core.so.5
#2  0x00007fa3748bee86 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#3  0x00007fa37487268a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#4  0x00007fa3746cf5e3 in QThread::exec() () from /lib64/libQt5Core.so.5
#5  0x00007fa37b1c54e5 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5
#6  0x00007fa3746d39ca in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5
#7  0x00007fa37665173a in start_thread () from /lib64/libpthread.so.0
#8  0x00007fa373ac6e7f in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fa3646b9700 (LWP 31097)):
#0  0x00007fa373abb001 in ppoll () from /lib64/libc.so.6
#1  0x00007fa3748bd971 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () from /lib64/libQt5Core.so.5
#2  0x00007fa3748bee86 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#3  0x00007fa37487268a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#4  0x00007fa3746cf5e3 in QThread::exec() () from /lib64/libQt5Core.so.5
#5  0x00007fa378df7fb9 in QDBusConnectionManager::run() () from /lib64/libQt5DBus.so.5
#6  0x00007fa3746d39ca in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5
#7  0x00007fa37665173a in start_thread () from /lib64/libpthread.so.0
#8  0x00007fa373ac6e7f in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fa3646bd940 (LWP 31092)):
[KCrash Handler]
#6  0x00007fa37487bfd9 in methodMatch(QMetaObject const*, int, QByteArray const&, int, QArgumentType const*) () from /lib64/libQt5Core.so.5
#7  0x00007fa37487ca4d in QMetaObjectPrivate::indexOfSignalRelative(QMetaObject const**, QByteArray const&, int, QArgumentType const*) () from /lib64/libQt5Core.so.5
#8  0x00007fa3748a0904 in QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) () from /lib64/libQt5Core.so.5
#9  0x00007fa37bfb2d2f in QScriptEnginePrivate::qobjectData(QObject*) () from /lib64/libQt5Script.so.5
#10 0x00007fa37bfb2df4 in QScriptEnginePrivate::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () from /lib64/libQt5Script.so.5
#11 0x00007fa37bfb30e2 in QScriptEngine::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () from /lib64/libQt5Script.so.5
#12 0x00007fa37c995f2c in KWin::effectWindowToScriptValue(QScriptEngine*, KWin::EffectWindow* const&) () from /lib64/libkwin.so.5
#13 0x00007fa37bfb3395 in QScriptEnginePrivate::create(QTJSC::ExecState*, int, void const*) () from /lib64/libQt5Script.so.5
#14 0x00007fa37bfdc0d6 in QScript::QObjectConnectionManager::execute(int, void**) () from /lib64/libQt5Script.so.5
#15 0x00007fa37bfe43e1 in QScript::QObjectConnectionManager::qt_metacall(QMetaObject::Call, int, void**) () from /lib64/libQt5Script.so.5
#16 0x00007fa37489a89b in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5
#17 0x00007fa37c5a47d8 in KWin::EffectsHandler::desktopPresenceChanged(KWin::EffectWindow*, int, int) () from /lib64/libkwineffects.so.10
#18 0x00007fa37c5a61a1 in KWin::EffectsHandler::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /lib64/libkwineffects.so.10
#19 0x00007fa37489b7e9 in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5
#20 0x00007fa3750b3ecc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#21 0x00007fa3750bb671 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#22 0x00007fa3748736fa in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#23 0x00007fa374875de0 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt5Core.so.5
#24 0x00007fa3748becfb in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#25 0x00007fa363e3a70d in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5XcbQpa.so.5
#26 0x00007fa37487268a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#27 0x00007fa37487a18c in QCoreApplication::exec() () from /lib64/libQt5Core.so.5
#28 0x00007fa37ccbc002 in kdemain () from /lib64/libkdeinit5_kwin_x11.so
#29 0x00007fa3739df401 in __libc_start_main () from /lib64/libc.so.6
#30 0x0000561475c8acca in _start ()

Reported using DrKonqi