Application: plasma-desktop (4.11.1)
KDE Platform Version: 4.11.1
Qt Version: 4.8.2
Operating System: Linux 3.2.0-53-generic x86_64
Distribution: Ubuntu 12.04.3 LTS

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

I clicked on the icon on the bottom left corner for "show activity manager."

In the activity manager, I clicked on the "Add Widgets" button.

The screen went black, and was informed that an application has crashed.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fc8c59fd780 (LWP 1723))]

Thread 6 (Thread 0x7fc8a3ad8700 (LWP 1726)):
#0  __pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:46
#1  __pthread_mutex_unlock (mutex=0x7fc89c000a60) at pthread_mutex_unlock.c:290
#2  0x00007fc8b8ed75d1 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fc8b8e9b98b in g_main_context_query () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fc8b8e9bfaa in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fc8b8e9c164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007fc8c1f58926 in QEventDispatcherGlib::processEvents (this=0x7fc89c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#7  0x00007fc8c1f27e62 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#8  0x00007fc8c1f280b7 in QEventLoop::exec (this=0x7fc8a3ad7dd0, flags=...) at kernel/qeventloop.cpp:204
#9  0x00007fc8c1e27077 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#10 0x00007fc8c1f07b6f in QInotifyFileSystemWatcherEngine::run (this=0xaabf20) at io/qfilesystemwatcher_inotify.cpp:248
#11 0x00007fc8c1e2a09b in QThreadPrivate::start (arg=0xaabf20) at thread/qthread_unix.cpp:307
#12 0x00007fc8b9598e9a in start_thread (arg=0x7fc8a3ad8700) at pthread_create.c:308
#13 0x00007fc8c53f0ccd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#14 0x0000000000000000 in ?? ()

Thread 5 (Thread 0x7fc8a27e8700 (LWP 1727)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fc8bed0b022 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007fc8bed0b059 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007fc8b9598e9a in start_thread (arg=0x7fc8a27e8700) at pthread_create.c:308
#4  0x00007fc8c53f0ccd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7fc816c5d700 (LWP 1729)):
#0  0x00007fc8c53e5313 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007fc8b8e9c036 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fc8b8e9c49a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fc817747406 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007fc8b8ebd9e5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fc8b9598e9a in start_thread (arg=0x7fc816c5d700) at pthread_create.c:308
#6  0x00007fc8c53f0ccd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7fc80f37b700 (LWP 1735)):
#0  0x00007fc8c53e5313 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007fc8b8e9c036 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fc8b8e9c164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fc8c1f58926 in QEventDispatcherGlib::processEvents (this=0x7fc7fc0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#4  0x00007fc8c1f27e62 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fc8c1f280b7 in QEventLoop::exec (this=0x7fc80f37add0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007fc8c1e27077 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#7  0x00007fc8c1f07b6f in QInotifyFileSystemWatcherEngine::run (this=0x1625eb0) at io/qfilesystemwatcher_inotify.cpp:248
#8  0x00007fc8c1e2a09b in QThreadPrivate::start (arg=0x1625eb0) at thread/qthread_unix.cpp:307
#9  0x00007fc8b9598e9a in start_thread (arg=0x7fc80f37b700) at pthread_create.c:308
#10 0x00007fc8c53f0ccd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fc80ca06700 (LWP 2229)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fc8c1e2a5ab in wait (time=18446744073709551615, this=0x1011ae0) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x100d750, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007fc8bdf7e2fb in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x10c3110, th=0x2bc6510) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007fc8bdf80aab in ThreadWeaver::WorkingHardState::applyForWork (this=0xfec460, th=0x2bc6510, previous=0x379d210) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007fc8bdf7f8b1 in ThreadWeaver::Thread::run (this=0x2bc6510) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007fc8c1e2a09b in QThreadPrivate::start (arg=0x2bc6510) at thread/qthread_unix.cpp:307
#7  0x00007fc8b9598e9a in start_thread (arg=0x7fc80ca06700) at pthread_create.c:308
#8  0x00007fc8c53f0ccd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#9  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fc8c59fd780 (LWP 1723)):
[KCrash Handler]
#6  deref (this=0x1d0000001c) at ../../include/QtCore/../../src/corelib/arch/qatomic_x86_64.h:133
#7  ~QString (this=0x38cbc00, __in_chrg=<optimized out>) at ../../include/QtCore/../../src/corelib/tools/qstring.h:880
#8  ~UrlContextData (this=0x38cbbb0, __in_chrg=<optimized out>) at qml/qdeclarativecontextscriptclass.cpp:79
#9  UrlContextData::~UrlContextData (this=0x38cbbb0, __in_chrg=<optimized out>) at qml/qdeclarativecontextscriptclass.cpp:79
#10 0x00007fc8c3b5f9f1 in QDeclarativeItem::~QDeclarativeItem (this=0x3fc8f20, __in_chrg=<optimized out>) at graphicsitems/qdeclarativeitem.cpp:1668
#11 0x00007fc8a1858a61 in ~QDeclarativeElement (this=0x3fc8f20, __in_chrg=<optimized out>) at /usr/include/qt4/QtDeclarative/qdeclarativeprivate.h:87
#12 QDeclarativePrivate::QDeclarativeElement<Plasma::FrameSvgItem>::~QDeclarativeElement (this=0x3fc8f20, __in_chrg=<optimized out>) at /usr/include/qt4/QtDeclarative/qdeclarativeprivate.h:87
#13 0x00007fc8c1f42978 in QObject::event (this=0x3fc8f20, e=<optimized out>) at kernel/qobject.cpp:1176
#14 0x00007fc8c12aa7b4 in notify_helper (e=0x371a210, receiver=0x3fc8f20, this=0xa93e90) at kernel/qapplication.cpp:4556
#15 QApplicationPrivate::notify_helper (this=0xa93e90, receiver=0x3fc8f20, e=0x371a210) at kernel/qapplication.cpp:4528
#16 0x00007fc8c12af583 in QApplication::notify (this=0xa88570, receiver=0x3fc8f20, e=0x371a210) at kernel/qapplication.cpp:4417
#17 0x00007fc8c2c0ed96 in KApplication::notify (this=0xa88570, receiver=0x3fc8f20, event=0x371a210) at ../../kdeui/kernel/kapplication.cpp:311
#18 0x00007fc8c1f2932c in QCoreApplication::notifyInternal (this=0xa88570, receiver=0x3fc8f20, event=0x371a210) at kernel/qcoreapplication.cpp:915
#19 0x00007fc8c1f2d10a in sendEvent (event=0x371a210, receiver=0x3fc8f20) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#20 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0xa221f0) at kernel/qcoreapplication.cpp:1539
#21 0x00007fc8c1f58493 in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#22 postEventSourceDispatch (s=<optimized out>) at kernel/qeventdispatcher_glib.cpp:279
#23 0x00007fc8b8e9bd53 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007fc8b8e9c0a0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#25 0x00007fc8b8e9c164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007fc8c1f588bf in QEventDispatcherGlib::processEvents (this=0xa23ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#27 0x00007fc8c1352cde in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#28 0x00007fc8c1f27e62 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#29 0x00007fc8c1f280b7 in QEventLoop::exec (this=0x7fffcb48e340, flags=...) at kernel/qeventloop.cpp:204
#30 0x00007fc8c1f2d407 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1187
#31 0x00007fc8c56f9fbf in kdemain (argc=1, argv=0x7fffcb48e728) at ../../../../plasma/desktop/shell/main.cpp:126
#32 0x00007fc8c531e76d in __libc_start_main (main=0x400640 <main(int, char**)>, argc=1, ubp_av=0x7fffcb48e728, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffcb48e718) at libc-start.c:226
#33 0x0000000000400671 in _start ()

Reported using DrKonqi