Are you using remote calendar or local ics file ?

no, just local, no remote system at all.

Can you install packages with debug symbols, and report a better backtrace?

Please ask for more info if you don't know how to do that.

Application: korganizer (4.4.5)
KDE Platform Version: 4.4.5 (KDE 4.4.5)
Qt Version: 4.6.3
Operating System: Linux 2.6.34-ARCH i686

-- Information about the crash:
Korganizer crashes when viewing event details.

I've opened friend's birthday event in Korganizer by double clicking on it. In the pop-up window I've clicked 'Show in Context' button which filtered out every non-birthday event in calendar. Then I've clicked 'Show in Context' button again and crash happened.

The crash can be reproduced every time.

 -- Backtrace:
Application: KOrganizer (korganizer), signal: Segmentation fault
[KCrash Handler]
#6  0xb734d40c in KCal::IncidenceBase::uid() const () from /usr/lib/libkcal.so.4
#7  0xb49b055f in KOEventViewer::showIncidenceContext() () from /usr/lib/libkorganizer_eventviewer.so.4
#8  0xb49b0a35 in KOEventViewer::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkorganizer_eventviewer.so.4
#9  0xb61d5f0a in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#10 0xb61e4feb in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#11 0xb7576017 in KDialog::user2Clicked (this=0x90f9f18) at /home/alexandernst/kdemod/core/kdelibs/src/build/kdeui/kdialog.moc:234
#12 0xb7576838 in KDialog::slotButtonClicked (this=0x90f9f18, button=8192) at /home/alexandernst/kdemod/core/kdelibs/src/kdelibs-4.4.5/kdeui/dialogs/kdialog.cpp:875
#13 0xb7576dbc in KDialog::qt_metacall (this=0x90f9f18, _c=QMetaObject::InvokeMetaMethod, _id=33, _a=0xbfa9e768) at /home/alexandernst/kdemod/core/kdelibs/src/build/kdeui/kdialog.moc:190
#14 0xb49b2412 in KOEventViewerDialog::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkorganizer_eventviewer.so.4
#15 0xb61d5f0a in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#16 0xb61e4feb in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#17 0xb61e8113 in QSignalMapper::mapped(int) () from /usr/lib/libQtCore.so.4
#18 0xb61e825f in QSignalMapper::map(QObject*) () from /usr/lib/libQtCore.so.4
#19 0xb61e841e in QSignalMapper::map() () from /usr/lib/libQtCore.so.4
#20 0xb61e890b in QSignalMapper::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#21 0xb61d5f0a in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#22 0xb61e4feb in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#23 0xb6af9fb9 in QAbstractButton::clicked(bool) () from /usr/lib/libQtGui.so.4
#24 0xb6815549 in ?? () from /usr/lib/libQtGui.so.4
#25 0xb6816be4 in ?? () from /usr/lib/libQtGui.so.4
#26 0xb6816e9e in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/libQtGui.so.4
#27 0xb647c3aa in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#28 0xb68160fe in QAbstractButton::event(QEvent*) () from /usr/lib/libQtGui.so.4
#29 0xb68b2e02 in QPushButton::event(QEvent*) () from /usr/lib/libQtGui.so.4
#30 0xb6425194 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#31 0xb6429d39 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#32 0xb760244a in KApplication::notify (this=0xbfa9f8b0, receiver=0x8f2f580, event=0xbfa9f128) at /home/alexandernst/kdemod/core/kdelibs/src/kdelibs-4.4.5/kdeui/kernel/kapplication.cpp:302
#33 0xb61cff1b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#34 0xb6426047 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/libQtGui.so.4
#35 0xb64ab09c in ?? () from /usr/lib/libQtGui.so.4
#36 0xb64aa1e9 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#37 0xb64d17f2 in ?? () from /usr/lib/libQtGui.so.4
#38 0xb4794f72 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#39 0xb4795750 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#40 0xb4795a04 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#41 0xb61faecc in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#42 0xb64d1435 in ?? () from /usr/lib/libQtGui.so.4
#43 0xb61cf169 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#44 0xb61cf3da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#45 0xb61d3cbf in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#46 0xb64228b7 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#47 0x0804eb10 in _start ()

Possible duplicates by query: bug 241979.

[Comment from a bug triager]
This bug report may be related or duplicate of bug 193654.

From bug 253175:
-- Information about the crash:
I have a truecrypt volume which contains all of my kontact files. I double
clicked on a calendar event and kontact crashed.

From bug 225876:
- What I was doing when the application crashed:
opening a birthday and use the link to KDE-Adressbook and change anything there
and comming back and use then the button show in calendar create allway this
crash.

From bug 253264:
-- Information about the crash:
Tried to view details on a birthday that was in my calendar - Kontact crashed
upon clicking on it

*** Bug 253175 has been marked as a duplicate of this bug. ***

*** Bug 225876 has been marked as a duplicate of this bug. ***

*** Bug 253264 has been marked as a duplicate of this bug. ***

*** Bug 265106 has been marked as a duplicate of this bug. ***

*** Bug 271802 has been marked as a duplicate of this bug. ***

Created attachment 60130 [details]
New crash information added by DrKonqi

kontact (4.4.10) on KDE Platform 4.6.00 (4.6.0) "release 6" using Qt 4.7.1

- What I was doing when the application crashed:

Simply clicked on "show in context", which then completely cleared my calendar of all events (in the view only, not in the actual data), and then Kontact crashed.

-- Backtrace (Reduced):
#7  0xb4b345cb in KCal::IncidenceBase::uid() const () from /usr/lib/libkcal.so.4
#8  0xad4fa5aa in KOEventViewer::showIncidenceContext() () from /usr/lib/libkorganizer_eventviewer.so.4
#9  0xad4faac6 in KOEventViewer::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkorganizer_eventviewer.so.4
[...]
#12 0xb71324f5 in KDialog::user2Clicked() () from /usr/lib/libkdeui.so.5
#13 0xb72cf2b0 in KDialog::slotButtonClicked(int) () from /usr/lib/libkdeui.so.5

Fixed with KCalCore in 4.6

Created attachment 61341 [details]
New crash information added by DrKonqi

kontact (4.4.11) on KDE Platform 4.6.3 (4.6.3) using Qt 4.7.3

- What I was doing when the application crashed:

I experience exactly the same behaviour as comment #4: Clicking twice on the "Show in Context" button in the event (birthday in my case) details consistently crashes Kontact.

-- Backtrace (Reduced):
#6  QString (other=..., this=0x7fff21a59110) at /usr/include/QtCore/qstring.h:728
#7  KCal::IncidenceBase::uid (this=0xc2e4ee0) at /usr/src/debug/kdepimlibs-4.6.3/kcal/incidencebase.cpp:185
#8  0x00007fb06f52a00f in KOEventViewer::showIncidenceContext (this=0xc1ee540) at /usr/src/debug/kdepim-4.4.11.1/korganizer/koeventviewer.cpp:175
#9  0x00007fb06f52a61d in KOEventViewer::qt_metacall (this=0xc1ee540, _c=QMetaObject::InvokeMetaMethod, _id=<optimized out>, _a=0x7fff21a59220) at /usr/src/debug/kdepim-4.4.11.1/x86_64-redhat-linux-gnu/korganizer/koeventviewer.moc:82
[...]
#11 0x00000031bf79ad90 in KDialog::slotButtonClicked (this=0xc36b270, button=8192) at /usr/src/debug/kdelibs-4.6.3/kdeui/dialogs/kdialog.cpp:896