Application: plasma-desktop (4.11.17)
KDE Platform Version: 4.14.6
Qt Version: 4.8.6
Operating System: Linux 3.16.7-7-desktop x86_64
Distribution: "openSUSE 13.2 (Harlequin) (x86_64)"

-- Information about the crash:
- What I was doing when the application crashed:
starting  up plasma causes plasma to crash. If an application (e.g. kmail) is started up during login this will cause the desktop to crash. I did activate public transport helper the session befor. 
- Unusual behavior I noticed:

screen goes black. Logout is still possible. Cursor is visible and moves normally. Any other desktop interaction is impossible. menues do not work. Logout with control plus alt plus del and then you select endsession.

The crash can be reproduced every time.

-- Backtrace:
Application: Shell del desktop di Plasma (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fd9b105c780 (LWP 4251))]

Thread 5 (Thread 0x7fd9817da700 (LWP 4262)):
#0  0x00007fd9af91d05f in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fd9a21ac8cb in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7fd9a24aaf00 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007fd9a21ac909 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007fd9af9190a4 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fd9ae68606d in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7fd8fbfff700 (LWP 4263)):
#0  0x00007fd9af91d05f in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fd9a3d3e686 in WTF::TCMalloc_PageHeap::scavengerThread() () from /usr/lib64/libQtWebKit.so.4
#2  0x00007fd9a3d3e6b9 in WTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /usr/lib64/libQtWebKit.so.4
#3  0x00007fd9af9190a4 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fd9ae68606d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fd8bb7fc700 (LWP 4264)):
#0  0x00007fd9af91d05f in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fd9a3ab0e7d in JSC::BlockAllocator::blockFreeingThreadMain() () from /usr/lib64/libQtWebKit.so.4
#2  0x00007fd9a3d661e6 in WTF::wtfThreadEntryPoint(void*) () from /usr/lib64/libQtWebKit.so.4
#3  0x00007fd9af9190a4 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fd9ae68606d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fd8afb08700 (LWP 4363)):
#0  0x00007fd9ae67dc3d in poll () from /lib64/libc.so.6
#1  0x00007fd9ab790be4 in ?? () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fd9ab790cec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fd9afcde0de in QEventDispatcherGlib::processEvents (this=0x7fd8a80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:452
#4  0x00007fd9afcafe6f in QEventLoop::processEvents (this=this@entry=0x7fd8afb07e20, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fd9afcb0165 in QEventLoop::exec (this=this@entry=0x7fd8afb07e20, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007fd9afbad0bf in QThread::exec (this=this@entry=0x1ae77d0) at thread/qthread.cpp:538
#7  0x00007fd9afc91783 in QInotifyFileSystemWatcherEngine::run (this=0x1ae77d0) at io/qfilesystemwatcher_inotify.cpp:265
#8  0x00007fd9afbaf79f in QThreadPrivate::start (arg=0x1ae77d0) at thread/qthread_unix.cpp:349
#9  0x00007fd9af9190a4 in start_thread () from /lib64/libpthread.so.0
#10 0x00007fd9ae68606d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fd9b105c780 (LWP 4251)):
[KCrash Handler]
#6  QMetaObject::cast (this=0x7fd9a4d0b880 <Plasma::Extender::staticMetaObject>, obj=0x600000) at kernel/qmetaobject.cpp:274
#7  0x00007fd9a4960b35 in qobject_cast<Plasma::Extender*> (object=<optimized out>) at /usr/include/QtCore/qobject.h:380
#8  qobject_cast<Plasma::Extender*> (o=<optimized out>) at /usr/include/QtDeclarative/qdeclarativeitem.h:206
#9  Plasma::PopupAppletPrivate::checkExtenderAppearance (this=this@entry=0x1b84450, f=f@entry=Plasma::Planar) at /usr/src/debug/kdelibs-4.14.6/plasma/popupapplet.cpp:191
#10 0x00007fd9a4962ae3 in Plasma::PopupAppletPrivate::popupConstraintsEvent (this=0x1b84450, constraints=...) at /usr/src/debug/kdelibs-4.14.6/plasma/popupapplet.cpp:212
#11 0x00007fd9a4909f27 in Plasma::Applet::flushPendingConstraintsEvents (this=0xe21e80) at /usr/src/debug/kdelibs-4.14.6/plasma/applet.cpp:1361
#12 0x00007fd9866ab4d6 in SystemTray::PlasmoidTask::forwardConstraintsEvent (this=0x7fd9a4d0b880 <Plasma::Extender::staticMetaObject>, constraints=<error reading variable: Cannot access memory at address 0x600000>) at /usr/src/debug/kde-workspace-4.11.17/plasma/generic/applets/systemtray/protocols/plasmoid/plasmoidtask.cpp:126
#13 0x00007fd9866aa0e1 in SystemTray::PlasmoidProtocol::forwardConstraintsEvent (this=0xcd94b0, constraints=..., host=host@entry=0xce1530) at /usr/src/debug/kde-workspace-4.11.17/plasma/generic/applets/systemtray/protocols/plasmoid/plasmoidtaskprotocol.cpp:54
#14 0x00007fd9866a2919 in SystemTray::Manager::forwardConstraintsEvent (this=<optimized out>, constraints=..., host=host@entry=0xce1530) at /usr/src/debug/kde-workspace-4.11.17/plasma/generic/applets/systemtray/core/manager.cpp:99
#15 0x00007fd9866b0ac1 in SystemTray::Applet::constraintsEvent (this=0xce1530, constraints=...) at /usr/src/debug/kde-workspace-4.11.17/plasma/generic/applets/systemtray/ui/applet.cpp:360
#16 0x00007fd9a4909f3d in Plasma::Applet::flushPendingConstraintsEvents (this=0xce1530) at /usr/src/debug/kdelibs-4.14.6/plasma/applet.cpp:1365
#17 0x00007fd9a4926aa8 in Plasma::ContainmentPrivate::initApplets (this=0xd6dfe0) at /usr/src/debug/kdelibs-4.14.6/plasma/containment.cpp:479
#18 0x00007fd9a49338dc in Plasma::CoronaPrivate::importLayout (this=0xb162e0, conf=..., mergeConfig=mergeConfig@entry=false) at /usr/src/debug/kdelibs-4.14.6/plasma/corona.cpp:1070
#19 0x00007fd9a49342da in Plasma::Corona::loadLayout (this=this@entry=0xadce00, configName=...) at /usr/src/debug/kdelibs-4.14.6/plasma/corona.cpp:281
#20 0x00007fd9a4934394 in Plasma::Corona::initializeLayout (this=this@entry=0xadce00, configName=...) at /usr/src/debug/kdelibs-4.14.6/plasma/corona.cpp:182
#21 0x00007fd99a6858f5 in PlasmaApp::corona (this=this@entry=0x92fc70, createIfMissing=createIfMissing@entry=true) at /usr/src/debug/kde-workspace-4.11.17/plasma/desktop/shell/plasmaapp.cpp:856
#22 0x00007fd99a685f05 in PlasmaApp::setupDesktop (this=0x92fc70) at /usr/src/debug/kde-workspace-4.11.17/plasma/desktop/shell/plasmaapp.cpp:314
#23 0x00007fd99a68a235 in PlasmaApp::qt_static_metacall (_o=0x92fc70, _id=6291456, _a=0x6, _c=<optimized out>) at /usr/src/debug/kde-workspace-4.11.17/build/plasma/desktop/shell/plasmaapp.moc:128
#24 0x00007fd9afcc959e in QObject::event (this=this@entry=0x92fc70, e=e@entry=0x96ec10) at kernel/qobject.cpp:1231
#25 0x00007fd9afcb573c in QCoreApplication::event (this=this@entry=0x92fc70, e=e@entry=0x96ec10) at kernel/qcoreapplication.cpp:1765
#26 0x00007fd9aee32733 in QApplication::event (this=0x92fc70, e=0x96ec10) at kernel/qapplication.cpp:2544
#27 0x00007fd9aee2d76c in QApplicationPrivate::notify_helper (this=this@entry=0x959d60, receiver=receiver@entry=0x92fc70, e=e@entry=0x96ec10) at kernel/qapplication.cpp:4565
#28 0x00007fd9aee33cad in QApplication::notify (this=this@entry=0x92fc70, receiver=receiver@entry=0x92fc70, e=e@entry=0x96ec10) at kernel/qapplication.cpp:4351
#29 0x00007fd9b0a54cea in KApplication::notify (this=0x92fc70, receiver=0x92fc70, event=0x96ec10) at /usr/src/debug/kdelibs-4.14.6/kdeui/kernel/kapplication.cpp:311
#30 0x00007fd9afcb12ad in QCoreApplication::notifyInternal (this=0x92fc70, receiver=receiver@entry=0x92fc70, event=event@entry=0x96ec10) at kernel/qcoreapplication.cpp:953
#31 0x00007fd9afcb457d in sendEvent (event=0x96ec10, receiver=0x92fc70) at kernel/qcoreapplication.h:231
#32 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x87e490) at kernel/qcoreapplication.cpp:1577
#33 0x00007fd9afcb4a23 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1470
#34 0x00007fd9afcde8fe in sendPostedEvents () at kernel/qcoreapplication.h:236
#35 postEventSourceDispatch (s=0x959ae0) at kernel/qeventdispatcher_glib.cpp:300
#36 0x00007fd9ab790a04 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#37 0x00007fd9ab790c48 in ?? () from /usr/lib64/libglib-2.0.so.0
#38 0x00007fd9ab790cec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#39 0x00007fd9afcde0be in QEventDispatcherGlib::processEvents (this=0x9598e0, flags=...) at kernel/qeventdispatcher_glib.cpp:450
#40 0x00007fd9aeeca676 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#41 0x00007fd9afcafe6f in QEventLoop::processEvents (this=this@entry=0x7fff2d8a0db0, flags=...) at kernel/qeventloop.cpp:149
#42 0x00007fd9afcb0165 in QEventLoop::exec (this=this@entry=0x7fff2d8a0db0, flags=...) at kernel/qeventloop.cpp:204
#43 0x00007fd9afcb55b9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#44 0x00007fd9aee2bf3c in QApplication::exec () at kernel/qapplication.cpp:3823
#45 0x00007fd99a670b94 in kdemain (argc=1, argv=0x8f5bf0) at /usr/src/debug/kde-workspace-4.11.17/plasma/desktop/shell/main.cpp:126
#46 0x0000000000408815 in _start ()

Reported using DrKonqi