Created attachment 93124 [details]
Error window screenshot.

I'm running Kubuntu 15.04, x86_64, KDE installed from Kubuntu backports.

Created attachment 93125 [details]
Report of a crash on kmail termination

After multiple attempts of starting kmail, it crashed after I pressed OK, just before terminating. Here's the backtrace:

[KCrash Handler]
#6  0x00007f4617de4267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#7  0x00007f4617de5eca in __GI_abort () at abort.c:89
#8  0x00007f4619409a8a in qt_message_output (msgType=msgType@entry=QtFatalMsg, buf=0x2639e08 "Fatal Error: Accessed global static 'QList<KMainWindow*> *sMemberList()' after destruction. Defined at ../../kdeui/widgets/kmainwindow.cpp:214") at global/qglobal.cpp:2386
#9  0x00007f4619409df9 in qt_message(QtMsgType, const char *, typedef __va_list_tag __va_list_tag *) (msgType=msgType@entry=QtFatalMsg, msg=msg@entry=0x7f461a79f090 "Fatal Error: Accessed global static '%s *%s()' after destruction. Defined at %s:%d", ap=ap@entry=0x7ffd12395fd0) at global/qglobal.cpp:2432
#10 0x00007f461940a6e1 in qFatal (msg=msg@entry=0x7f461a79f090 "Fatal Error: Accessed global static '%s *%s()' after destruction. Defined at %s:%d") at global/qglobal.cpp:2615
#11 0x00007f461a702a4f in operator-> (this=<synthetic pointer>) at ../../kdeui/widgets/kmainwindow.cpp:214
#12 operator* (this=<synthetic pointer>) at ../../kdeui/widgets/kmainwindow.cpp:214
#13 KMainWindow::memberList () at ../../kdeui/widgets/kmainwindow.cpp:1218
#14 0x00007f4619943048 in KMKernel::dumpDeadLetters (this=<optimized out>) at ../../kmail/kmkernel.cpp:1322
#15 0x00007f4619944e57 in kmCrashHandler (sigId=<optimized out>) at ../../kmail/kmkernel.cpp:1181
#16 0x00007f461a6a5a20 in KCrash::defaultCrashHandler (sig=6) at ../../kdeui/util/kcrash.cpp:340
#17 <signal handler called>
#18 0x00007f4617de4267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#19 0x00007f4617de5eca in __GI_abort () at abort.c:89
#20 0x00007f4619409a8a in qt_message_output (msgType=msgType@entry=QtFatalMsg, buf=0x2f41ef8 "Fatal Error: Accessed global static 'KernelPrivate *sInstance()' after destruction. Defined at ../../mailcommon/kernel/mailkernel.cpp:58") at global/qglobal.cpp:2386
#21 0x00007f4619409df9 in qt_message(QtMsgType, const char *, typedef __va_list_tag __va_list_tag *) (msgType=msgType@entry=QtFatalMsg, msg=msg@entry=0x7f46135f9148 "Fatal Error: Accessed global static '%s *%s()' after destruction. Defined at %s:%d", ap=ap@entry=0x7ffd12396d00) at global/qglobal.cpp:2432
#22 0x00007f461940a6e1 in qFatal (msg=msg@entry=0x7f46135f9148 "Fatal Error: Accessed global static '%s *%s()' after destruction. Defined at %s:%d") at global/qglobal.cpp:2615
#23 0x00007f46135365ff in operator-> (this=<optimized out>) at ../../mailcommon/kernel/mailkernel.cpp:58
#24 MailCommon::Kernel::self () at ../../mailcommon/kernel/mailkernel.cpp:75
#25 0x00007f4613583383 in MailCommon::FolderCollection::writeConfig (this=this@entry=0x2eaf0a0) at ../../mailcommon/folder/foldercollection.cpp:218
#26 0x00007f4613583ba2 in MailCommon::FolderCollection::~FolderCollection (this=0x2eaf0a0, __in_chrg=<optimized out>) at ../../mailcommon/folder/foldercollection.cpp:84
#27 0x00007f4613583caf in ~FolderCollection (this=0x2eaf0a0, __in_chrg=<optimized out>) at ../../mailcommon/folder/foldercollection.cpp:86
#28 deref (value=0x2eaf0a0, d=0x2ea2660) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:342
#29 deref (this=<optimized out>) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:336
#30 ~ExternalRefCount (this=<optimized out>, __in_chrg=<optimized out>) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:401
#31 ~QSharedPointer (this=<optimized out>, __in_chrg=<optimized out>) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:466
#32 QMap<long long, QSharedPointer<MailCommon::FolderCollection> >::freeData (x=0x2ea5d80, this=<optimized out>) at /usr/include/qt4/QtCore/qmap.h:652
#33 0x00007f4617de90da in __cxa_finalize (d=0x7f4613858a48) at cxa_finalize.c:56
#34 0x00007f46135340a3 in __do_global_dtors_aux () from /usr/lib/libmailcommon.so.4
#35 0x00007ffd12397870 in ?? ()
#36 0x00007f461aa92bb7 in _dl_fini () at dl-fini.c:252

This bug has never been confirmed for a KDE PIM version that is based on KDE Frameworks (5.x). Those versions differ significantly from the old 4.x series. Therefore, I plan to close it in around two or three months. In the meantime, it is set to WAITINGFORINFO to give reporters the oportunity to check if it is still valid. As soon as someone confirms it for a recent version (at least 5.1, ideally even more recent), I'll gladly reopen it.

Please understand that we lack the manpower to triage bugs reported for versions almost two years beyond their end of life.

Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.1 aka 15.12, preferably more recent), please open a new one unless it already exists. Thank you for all your input.