I clicked on the control bar - and then it crashed as follows. I do get regularly crashes, say, every fortnight - but with no reproducible pattern. Crash report shows this time the following:

Application: plasmashell (5.5.5)
Qt Version: 5.5.1
Operating System: Linux 4.4.3-1-default x86_64
Distribution: "openSUSE Tumbleweed (20160307) (x86_64)"

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
84	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7f2a3c9b18c0 (LWP 16687))]

Thread 7 (Thread 0x7f2a1f3ea700 (LWP 16722)):
#0  0x00007f2a3262d8c0 in g_main_context_prepare (context=context@entry=0x7f2a18000990, priority=priority@entry=0x7f2a1f3e9bd8) at gmain.c:3442
#1  0x00007f2a3262e1c3 in g_main_context_iterate (context=context@entry=0x7f2a18000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3820
#2  0x00007f2a3262e39c in g_main_context_iteration (context=0x7f2a18000990, may_block=may_block@entry=1) at gmain.c:3901
#3  0x00007f2a3684f52b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f2a180008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f2a1f3e9cf0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f2a36625b1c in QThread::exec() (this=this@entry=0xb4f2a0) at thread/qthread.cpp:503
#6  0x00007f2a398f47b5 in QQmlThreadPrivate::run() (this=0xb4f2a0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/ftw/qqmlthread.cpp:141
#7  0x00007f2a3662a94f in QThreadPrivate::start(void*) (arg=0xb4f2a0) at thread/qthread_unix.cpp:331
#8  0x00007f2a357414a4 in start_thread (arg=0x7f2a1f3ea700) at pthread_create.c:334
#9  0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f2a11ec3700 (LWP 16727)):
#0  0x00007f2a32671554 in g_mutex_unlock (mutex=0x7f2a0c000990) at gthread-posix.c:1350
#1  0x00007f2a3262e15d in g_main_context_iterate (context=context@entry=0x7f2a0c000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3788
#2  0x00007f2a3262e39c in g_main_context_iteration (context=0x7f2a0c000990, may_block=may_block@entry=1) at gmain.c:3901
#3  0x00007f2a3684f52b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f2a0c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f2a11ec2cf0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f2a36625b1c in QThread::exec() (this=this@entry=0xeb5b30) at thread/qthread.cpp:503
#6  0x00007f2a398f47b5 in QQmlThreadPrivate::run() (this=0xeb5b30) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/ftw/qqmlthread.cpp:141
#7  0x00007f2a3662a94f in QThreadPrivate::start(void*) (arg=0xeb5b30) at thread/qthread_unix.cpp:331
#8  0x00007f2a357414a4 in start_thread (arg=0x7f2a11ec3700) at pthread_create.c:334
#9  0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f2a0bfff700 (LWP 16729)):
#0  0x00007f2a36622d1a in QMutex::lock() (currentValue=<synthetic pointer>, newValue=0x1, expectedValue=0x0, _q_value=@0xf8be68: 0x1) at ../../src/corelib/arch/qatomic_x86.h:259
#1  0x00007f2a36622d1a in QMutex::lock() (currentValue=<synthetic pointer>, newValue=<optimized out>, expectedValue=0x0, _q_value=@0xf8be68: 0x1) at ../../src/corelib/thread/qgenericatomic.h:166
#2  0x00007f2a36622d1a in QMutex::lock() (currentValue=<synthetic pointer>, newValue=<optimized out>, expectedValue=0x0, this=0xf8be68, this@entry=0x29) at ../../src/corelib/thread/qbasicatomic.h:278
#3  0x00007f2a36622d1a in QMutex::lock() (current=<synthetic pointer>, this=0xf8be68, this@entry=0x29) at thread/qmutex.h:82
#4  0x00007f2a36622d1a in QMutex::lock() (this=this@entry=0xf8be68) at thread/qmutex.cpp:212
#5  0x00007f2a3684edb9 in postEventSourceCheck(GSource*) (m=0xf8be68, this=<synthetic pointer>) at ../../src/corelib/thread/qmutex.h:128
#6  0x00007f2a3684edb9 in postEventSourceCheck(GSource*) (this=0xf8be40) at ../../src/corelib/thread/qthread_p.h:240
#7  0x00007f2a3684edb9 in postEventSourceCheck(GSource*) (timeout=<synthetic pointer>, s=0x7f2a040012d0) at kernel/qeventdispatcher_glib.cpp:254
#8  0x00007f2a3684edb9 in postEventSourceCheck(GSource*) (source=0x7f2a040012d0) at kernel/qeventdispatcher_glib.cpp:264
#9  0x00007f2a3262dd11 in g_main_context_check (context=context@entry=0x7f2a04000990, max_priority=2147483647, fds=fds@entry=0x7f2a04003070, n_fds=n_fds@entry=1) at gmain.c:3681
#10 0x00007f2a3262e238 in g_main_context_iterate (context=context@entry=0x7f2a04000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3837
#11 0x00007f2a3262e39c in g_main_context_iteration (context=0x7f2a04000990, may_block=may_block@entry=1) at gmain.c:3901
#12 0x00007f2a3684f52b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f2a040008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#13 0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f2a0bffecf0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#14 0x00007f2a36625b1c in QThread::exec() (this=this@entry=0xfa8870) at thread/qthread.cpp:503
#15 0x00007f2a398f47b5 in QQmlThreadPrivate::run() (this=0xfa8870) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/ftw/qqmlthread.cpp:141
#16 0x00007f2a3662a94f in QThreadPrivate::start(void*) (arg=0xfa8870) at thread/qthread_unix.cpp:331
#17 0x00007f2a357414a4 in start_thread (arg=0x7f2a0bfff700) at pthread_create.c:334
#18 0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f2a0abd7700 (LWP 16741)):
#0  0x00007f2a3574707f in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f2a3c09ca84 in QTWTF::TCMalloc_PageHeap::scavengerThread() (this=0x7f2a3c383ea0 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007f2a3c09cac9 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007f2a357414a4 in start_thread (arg=0x7f2a0abd7700) at pthread_create.c:334
#4  0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f2983fff700 (LWP 16768)):
#0  0x00007f2a32671554 in g_mutex_unlock (mutex=0x7f297c000990) at gthread-posix.c:1350
#1  0x00007f2a3262d940 in g_main_context_prepare (context=context@entry=0x7f297c000990, priority=priority@entry=0x7f2983ffeb98) at gmain.c:3507
#2  0x00007f2a3262e1c3 in g_main_context_iterate (context=context@entry=0x7f297c000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3820
#3  0x00007f2a3262e39c in g_main_context_iteration (context=0x7f297c000990, may_block=may_block@entry=1) at gmain.c:3901
#4  0x00007f2a3684f52b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f297c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f2983ffecb0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f2a36625b1c in QThread::exec() (this=this@entry=0x11bea90) at thread/qthread.cpp:503
#7  0x00007f2a3a47ae42 in QQuickPixmapReader::run() (this=0x11bea90) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/util/qquickpixmapcache.cpp:760
#8  0x00007f2a3662a94f in QThreadPrivate::start(void*) (arg=0x11bea90) at thread/qthread_unix.cpp:331
#9  0x00007f2a357414a4 in start_thread (arg=0x7f2983fff700) at pthread_create.c:334
#10 0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f2977732700 (LWP 16959)):
#0  0x00007f2a35f3a49d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f2a3262e294 in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f29700048d0, timeout=<optimized out>, context=0x7f2970000990) at gmain.c:4135
#2  0x00007f2a3262e294 in g_main_context_iterate (context=context@entry=0x7f2970000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3835
#3  0x00007f2a3262e39c in g_main_context_iteration (context=0x7f2970000990, may_block=may_block@entry=1) at gmain.c:3901
#4  0x00007f2a3684f52b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f29700008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f2977731cd0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f2a36625b1c in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f2979e64e47 in KCupsConnection::run() () at /usr/lib64/libkcupslib.so
#8  0x00007f2a3662a94f in QThreadPrivate::start(void*) (arg=0x31c4e00) at thread/qthread_unix.cpp:331
#9  0x00007f2a357414a4 in start_thread (arg=0x7f2977732700) at pthread_create.c:334
#10 0x00007f2a35f42ded in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f2a3c9b18c0 (LWP 16687)):
[KCrash Handler]
#6  0x00007f2a3987eba4 in QQmlContext::isValid() const (this=0x3e1bc70) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/qqmlcontext.cpp:223
#7  0x00007f2a39870329 in QQmlExpression::QQmlExpression(QQmlScriptString const&, QQmlContext*, QObject*, QObject*) (this=<optimized out>, script=..., ctxt=0x0, scope=0x0, parent=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/qqmlexpression.cpp:142
#8  0x00007f2a3a459514 in QQuickScriptActionPrivate::execute() (this=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/util/qquickanimation.cpp:990
#9  0x00007f2a39928c5d in QAbstractAnimationJob::setState(QAbstractAnimationJob::State) (this=0x4e04720, newState=QAbstractAnimationJob::Running) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qabstractanimationjob.cpp:360
#10 0x00007f2a3992a3aa in QSequentialAnimationGroupJob::activateCurrentAnimation(bool) (this=0x4d295c0, intermediate=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qsequentialanimationgroupjob.cpp:310
#11 0x00007f2a3992a49c in QSequentialAnimationGroupJob::uncontrolledAnimationFinished(QAbstractAnimationJob*) (this=0x4d295c0, animation=0x4fe0bf0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qsequentialanimationgroupjob.cpp:326
#12 0x00007f2a3992828c in QAbstractAnimationJob::finished() (this=this@entry=0x4fe0bf0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qabstractanimationjob.cpp:594
#13 0x00007f2a39928d68 in QAbstractAnimationJob::setState(QAbstractAnimationJob::State) (this=0x4fe0bf0, newState=newState@entry=QAbstractAnimationJob::Stopped) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qabstractanimationjob.cpp:393
#14 0x00007f2a39928da7 in QAbstractAnimationJob::stop() (this=this@entry=0x4fe0bf0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/animations/qabstractanimationjob.cpp:530
#15 0x00007f2a3a499de9 in QQuickAnimatorProxyJob::setWindow(QQuickWindow*) (this=0x4fe0be0, window=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/util/qquickanimatorjob.cpp:158
#16 0x00007f2a36828f5a in QMetaObject::activate(QObject*, int, int, void**) (sender=0x4ad1900, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=11, argv=argv@entry=0x7ffd77b4c660) at kernel/qobject.cpp:3713
#17 0x00007f2a36829757 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=<optimized out>, m=m@entry=0x7f2a3a924160 <QQuickItem::staticMetaObject>, local_signal_index=local_signal_index@entry=11, argv=argv@entry=0x7ffd77b4c660) at kernel/qobject.cpp:3578
#18 0x00007f2a3a4fb622 in QQuickItem::windowChanged(QQuickWindow*) (this=<optimized out>, _t1=0x0) at .moc/moc_qquickitem.cpp:1044
#19 0x00007f2a3a506dbb in QQuickItemPrivate::derefWindow() (this=this@entry=0x499be40) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/items/qquickitem.cpp:2852
#20 0x00007f2a3a508d3c in QQuickItem::setParentItem(QQuickItem*) (this=this@entry=0x4ad1900, parentItem=parentItem@entry=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/items/qquickitem.cpp:2527
#21 0x00007f2a3a5091d6 in QQuickItem::~QQuickItem() (this=0x4ad1900, __in_chrg=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/items/qquickitem.cpp:2239
#22 0x00007f2a3a522da6 in QQmlPrivate::QQmlElement<QQuickItem>::~QQmlElement() (this=0x4ad1900, __in_chrg=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/qqmlprivate.h:98
#23 0x00007f2a3a522da6 in QQmlPrivate::QQmlElement<QQuickItem>::~QQmlElement() (this=0x4ad1900, __in_chrg=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/qml/qqmlprivate.h:98
#24 0x00007f2a36829d70 in QObject::event(QEvent*) (this=this@entry=0x4ad1900, e=e@entry=0x587a950) at kernel/qobject.cpp:1230
#25 0x00007f2a3a507d8b in QQuickItem::event(QEvent*) (this=0x4ad1900, ev=0x587a950) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/quick/items/qquickitem.cpp:7317
#26 0x00007f2a37b718cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#27 0x00007f2a37b769d6 in QApplication::notify(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#28 0x00007f2a367fbcd3 in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7ffd77b4ce40, receiver=0x4ad1900, event=event@entry=0x587a950) at kernel/qcoreapplication.cpp:965
#29 0x00007f2a367fdff6 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (event=0x587a950, receiver=<optimized out>) at kernel/qcoreapplication.h:224
#30 0x00007f2a367fdff6 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0xa5f7b0) at kernel/qcoreapplication.cpp:1593
#31 0x00007f2a367fe4d8 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#32 0x00007f2a3684f103 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0xaab4c0) at kernel/qeventdispatcher_glib.cpp:271
#33 0x00007f2a3262e0c7 in g_main_context_dispatch (context=0x7f2a200016f0) at gmain.c:3154
#34 0x00007f2a3262e0c7 in g_main_context_dispatch (context=context@entry=0x7f2a200016f0) at gmain.c:3769
#35 0x00007f2a3262e2f8 in g_main_context_iterate (context=context@entry=0x7f2a200016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3840
#36 0x00007f2a3262e39c in g_main_context_iteration (context=0x7f2a200016f0, may_block=may_block@entry=1) at gmain.c:3901
#37 0x00007f2a3684f50f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0xa5f710, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#38 0x00007f2a367f961a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffd77b4ccf0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#39 0x00007f2a368012dd in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#40 0x00000000004365be in main ()

Reproducible: Always