Version:           2.1.0 (using KDE 4.6.4) 
OS:                Linux

Sometimes the "version conflict"-dialogue does not accept clicks, i.e. there is no way to get rid of it but kill kontact.

user  19551  0.2  8.0 763600 165908 ?       Sl   Jul02   3:54 /usr/bin/kontact

I attached gdb to kontact and it gave me the following backtrace:

(gdb) bt
#0  0x00007f765c16d503 in __poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=<value optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f7655bea114 in g_main_context_poll (context=0x63b8e0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:3404
#2  g_main_context_iterate (context=0x63b8e0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:3086
#3  0x00007f7655bea650 in g_main_context_iteration (context=0x63b8e0, may_block=1) at gmain.c:3154
#4  0x00007f765d54622f in QEventDispatcherGlib::processEvents (this=0x6133b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#5  0x00007f765c988bae in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#6  0x00007f765d51a8d2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#7  0x00007f765d51aae5 in QEventLoop::exec (this=0x7fff317caae0, flags=...) at kernel/qeventloop.cpp:201
#8  0x00007f765d9102d6 in KJob::exec (this=0x2c7a800) at /usr/src/debug/kdelibs-4.6.4/kdecore/jobs/kjob.cpp:204
#9  0x00007f764217475d in KMMainWidget::slotEndCheckMail (this=0xd2e990) at /usr/src/debug/kdepim-4.6.0/kmail/kmmainwidget.cpp:387
#10 0x00007f7642175f6d in KMMainWidget::qt_metacall (this=0xd2e990, _c=QMetaObject::InvokeMetaMethod, _id=27, _a=0x7fff317caea0) at /usr/src/debug/kdepim-4.6.0/build/kmail/kmmainwidget.moc:369
#11 0x00007f765d52fa5f in QMetaObject::activate (sender=0xb3b1d0, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3278
#12 0x00007f7642124bfc in KMKernel::slotProgressItemCompletedOrCanceled (this=0xb3b1d0, item=<value optimized out>) at /usr/src/debug/kdepim-4.6.0/kmail/kmkernel.cpp:1660
#13 0x00007f76421308cc in KMKernel::qt_metacall (this=0xb3b1d0, _c=QMetaObject::InvokeMetaMethod, _id=36, _a=0x7fff317cb110) at /usr/src/debug/kdepim-4.6.0/build/kmail/kmkernel.moc:205
#14 0x00007f765d52fa5f in QMetaObject::activate (sender=0x8d2c40, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff317cb110) at kernel/qobject.cpp:3278
#15 0x00007f7659e283c2 in KPIM::ProgressManager::progressItemCompleted (this=<value optimized out>, _t1=0x81778e0) at /usr/src/debug/kdepim-4.6.0/build/libkdepim/progressmanager.moc:272
#16 0x00007f7659e28e33 in KPIM::ProgressManager::qt_metacall (this=0x8d2c40, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff317cb230)
    at /usr/src/debug/kdepim-4.6.0/build/libkdepim/progressmanager.moc:246
#17 0x00007f765d52fa5f in QMetaObject::activate (sender=0x81778e0, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff317cb230) at kernel/qobject.cpp:3278
#18 0x00007f7659e27f92 in KPIM::ProgressItem::progressItemCompleted (this=<value optimized out>, _t1=0x81778e0) at /usr/src/debug/kdepim-4.6.0/build/libkdepim/progressmanager.moc:121
#19 0x00007f7659e28670 in KPIM::ProgressItem::setComplete (this=0x81778e0) at /usr/src/debug/kdepim-4.6.0/libkdepim/progressmanager.cpp:56
#20 0x00007f7659e29bad in KPIM::AgentProgressMonitor::Private::instanceStatusChanged (this=0x6ebb3a0, instance=...) at /usr/src/debug/kdepim-4.6.0/libkdepim/agentprogressmonitor.cpp:86
#21 0x00007f7659e29c8a in KPIM::AgentProgressMonitor::qt_metacall (this=0x718c360, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff317cb380)
    at /usr/src/debug/kdepim-4.6.0/build/libkdepim/agentprogressmonitor.moc:78
#22 0x00007f765d52fa5f in QMetaObject::activate (sender=0xad9760, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff317cb380) at kernel/qobject.cpp:3278
#23 0x00007f7659348fc5 in Akonadi::AgentManager::instanceStatusChanged (this=<value optimized out>, _t1=<value optimized out>) at /usr/src/debug/kdepimlibs-4.6.4/build/akonadi/agentmanager.moc:177
#24 0x00007f7659380bc1 in Akonadi::AgentManagerPrivate::agentInstanceStatusChanged (this=0xb757c0, identifier=<value optimized out>, status=0, msg=...)
    at /usr/src/debug/kdepimlibs-4.6.4/akonadi/agentmanager.cpp:129
#25 0x00007f76593825ee in Akonadi::AgentManager::qt_metacall (this=0xad9760, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff317cb500)
    at /usr/src/debug/kdepimlibs-4.6.4/build/akonadi/agentmanager.moc:131
---Type <return> to continue, or q <return> to quit---
#26 0x00007f765d52fa5f in QMetaObject::activate (sender=0x9c0a80, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff317cb500) at kernel/qobject.cpp:3278
#27 0x00007f765943746b in OrgFreedesktopAkonadiAgentManagerInterface::agentInstanceStatusChanged (this=<value optimized out>, _t1=<value optimized out>, _t2=0, _t3=<value optimized out>)
    at /usr/src/debug/kdepimlibs-4.6.4/build/akonadi/agentmanagerinterface.moc:285
#28 0x00007f7659437925 in OrgFreedesktopAkonadiAgentManagerInterface::qt_metacall (this=0x9c0a80, _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0x7fff317cbe00)
    at /usr/src/debug/kdepimlibs-4.6.4/build/akonadi/agentmanagerinterface.moc:167
#29 0x00007f76596d3568 in QDBusConnectionPrivate::deliverCall (this=0x62d3e0, object=0x9c0a80, msg=..., metaTypes=..., slotIdx=12) at qdbusintegrator.cpp:941
#30 0x00007f76596ddb8f in QDBusCallDeliveryEvent::placeMetaCall (this=<value optimized out>, object=<value optimized out>) at qdbusintegrator_p.h:103
#31 0x00007f765d52f37a in QObject::event (this=0x9c0a80, e=<value optimized out>) at kernel/qobject.cpp:1217
#32 0x00007f765c8e3144 in QApplicationPrivate::notify_helper (this=0x643860, receiver=0x9c0a80, e=0x65e1350) at kernel/qapplication.cpp:4462
#33 0x00007f765c8eb6fa in QApplication::notify (this=<value optimized out>, receiver=0x9c0a80, e=0x65e1350) at kernel/qapplication.cpp:4341
#34 0x00007f765de7e3c6 in KApplication::notify (this=0x7fff317cd370, receiver=0x9c0a80, event=0x65e1350) at /usr/src/debug/kdelibs-4.6.4/kdeui/kernel/kapplication.cpp:311
#35 0x00007f765d51b47c in QCoreApplication::notifyInternal (this=0x7fff317cd370, receiver=0x9c0a80, event=0x65e1350) at kernel/qcoreapplication.cpp:731
#36 0x00007f765d51ec75 in sendEvent (receiver=0x0, event_type=0, data=0x60d4a0) at kernel/qcoreapplication.h:215
#37 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x60d4a0) at kernel/qcoreapplication.cpp:1372
#38 0x00007f765d546093 in sendPostedEvents (s=0x63b9c0) at kernel/qcoreapplication.h:220
#39 postEventSourceDispatch (s=0x63b9c0) at kernel/qeventdispatcher_glib.cpp:277
#40 0x00007f7655be9bd3 in g_main_dispatch (context=0x63b8e0) at gmain.c:2440
#41 g_main_context_dispatch (context=0x63b8e0) at gmain.c:3013
#42 0x00007f7655bea3b0 in g_main_context_iterate (context=0x63b8e0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:3091
#43 0x00007f7655bea650 in g_main_context_iteration (context=0x63b8e0, may_block=1) at gmain.c:3154
#44 0x00007f765d54622f in QEventDispatcherGlib::processEvents (this=0x6133b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#45 0x00007f765c988bae in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#46 0x00007f765d51a8d2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#47 0x00007f765d51aae5 in QEventLoop::exec (this=0x7fff317cc830, flags=...) at kernel/qeventloop.cpp:201
#48 0x00007f765cd9652e in QDialog::exec (this=0x7fff317cc8a0) at dialogs/qdialog.cpp:552
#49 0x00007f76593e6e0e in Akonadi::ConflictHandler::resolve (this=0x6d0b5f0) at /usr/src/debug/kdepimlibs-4.6.4/akonadi/conflicthandling/conflicthandler.cpp:80
#50 0x00007f76593e6fcc in Akonadi::ConflictHandler::qt_metacall (this=0x6d0b5f0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x4fbe820)
    at /usr/src/debug/kdepimlibs-4.6.4/build/akonadi/conflicthandler_p.moc:91
#51 0x00007f765d52f37a in QObject::event (this=0x6d0b5f0, e=<value optimized out>) at kernel/qobject.cpp:1217
#52 0x00007f765c8e3144 in QApplicationPrivate::notify_helper (this=0x643860, receiver=0x6d0b5f0, e=0x8143e60) at kernel/qapplication.cpp:4462
---Type <return> to continue, or q <return> to quit---
#53 0x00007f765c8eb6fa in QApplication::notify (this=<value optimized out>, receiver=0x6d0b5f0, e=0x8143e60) at kernel/qapplication.cpp:4341
#54 0x00007f765de7e3c6 in KApplication::notify (this=0x7fff317cd370, receiver=0x6d0b5f0, event=0x8143e60) at /usr/src/debug/kdelibs-4.6.4/kdeui/kernel/kapplication.cpp:311
#55 0x00007f765d51b47c in QCoreApplication::notifyInternal (this=0x7fff317cd370, receiver=0x6d0b5f0, event=0x8143e60) at kernel/qcoreapplication.cpp:731
#56 0x00007f765d51ec75 in sendEvent (receiver=0x0, event_type=0, data=0x60d4a0) at kernel/qcoreapplication.h:215
#57 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x60d4a0) at kernel/qcoreapplication.cpp:1372
#58 0x00007f765d546093 in sendPostedEvents (s=0x63b9c0) at kernel/qcoreapplication.h:220
#59 postEventSourceDispatch (s=0x63b9c0) at kernel/qeventdispatcher_glib.cpp:277
#60 0x00007f7655be9bd3 in g_main_dispatch (context=0x63b8e0) at gmain.c:2440
#61 g_main_context_dispatch (context=0x63b8e0) at gmain.c:3013
#62 0x00007f7655bea3b0 in g_main_context_iterate (context=0x63b8e0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:3091
#63 0x00007f7655bea650 in g_main_context_iteration (context=0x63b8e0, may_block=1) at gmain.c:3154
#64 0x00007f765d54622f in QEventDispatcherGlib::processEvents (this=0x6133b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#65 0x00007f765c988bae in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#66 0x00007f765d51a8d2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#67 0x00007f765d51aae5 in QEventLoop::exec (this=0x7fff317cd2c0, flags=...) at kernel/qeventloop.cpp:201
#68 0x00007f765d51ef2b in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#69 0x000000000040416f in main (argc=1, argv=0x7fff317cd998) at /usr/src/debug/kdepim-4.6.0/kontact/src/main.cpp:218

HAving to kill kontact can lead to data loss.

Reproducible: Sometimes

Steps to Reproduce:
Wait until you get the "version conflict" dialogue. There are plenty of bugs filed on what triggers them, e.g. changing an email's status while it is fetched from the server.

Actual Results:  
blocking GUI? (@bugzilla admins: Most the times forcing the reporter to fill in these fiels is useless!)

Expected Results:  
Guess! Non-blocking GUI. No offense to the kmail developers, not their fault that these fields are required now, though being pretty useless most of the time)