This crash happens when QFontDatabasePrivate gets desroyed in a different thread that created it. This can happen if a last handle to a Qt-using library is closed by a thread other than the Qt GUI thread. 

ThreadPanicBreakPoint(int 0x00000000, TDesC8 & {...}) line 143
DJitCrashHandler::HandleEvent(TKernelEvent EEventKillThread) line 178 + 15 bytes
DKernelEventHandler::Dispatch(void * 0x00000000, void * 0x00aa8680, TKernelEvent EEventKillThread) line 1670 + 18 bytes
DThread::Exit() line 618 + 12 bytes
DThread::EpocThreadExitHandler(NThread * 0x00aa8940) line 569
NThreadBase::Exit() line 1057 + 6 bytes
NThreadBase::DoCsFunction() line 643
NFastMutex::Signal() line 109
NKern::ThreadKill(NFastMutex * 0x008c73c8, NThread * 0x00aa8940) line 1498
DThread::Die(TDesC8 & {...}, int 0x00000000, TExitType EExitPanic) line 693 + 16 bytes
K::PanicCurrentThread(int 0x00000000) line 770
Win32PreprocessHandler(unsigned long 0x00000009, int * 0x297dec4c) line 108 + 7 bytes
Dispatch() line 66 + 8 bytes
RSessionBase::SendSync(TIpcArgs * 0x297dec94, int 0x00000027) line 2476 + 20 bytes
RSessionBase::DoSendReceive(TIpcArgs * 0x297dec94, int 0x00000027) line 38 + 14 bytes
RSubSessionBase::DoSendReceive(TIpcArgs * 0x00000000, int 0x00000027) line 255 + 15 bytes
RSubSessionBase::SendReceive(int 0x00000027) line 4287 + 30 bytes
RFile::Flush() line 1351 + 10 bytes
CFileDesc::DoSync() line 694 + 11 bytes
CFileDesc::FinalClose() line 392 + 8 bytes
CFileDescBase::Close() line 346 + 15 bytes
CFileTable::close(int & 0x00000000, int 0x00000004) line 260 + 8 bytes
CFileTable::userclose(int & 0x00000000, int 0x00000004) line 241
CLocalSystemInterface::close(int & 0x00000000, int 0x00000004) line 157 + 17 bytes
_close_r(int 0x00000004, _reent * 0x29a007d0) line 154 + 18 bytes
__sclose(void * 0x29a00ad8) line 86 + 16 bytes
fclose(__sFILE * 0x29a00ad8) line 83 + 21 bytes
ITYPERAST! 1c05bb6c()
ITYPERAST! 1c071ff1()
ITYPERAST! 1c057465()
ITYPERAST! 1c07306d()
ITYPERAST! 1c05684c()
ITYPERAST! 1c052e20()
ITYPERAST! 1c05133a()
ITYPERAST! 1c05445e()
CArrayPtr<COpenFontFile>::ResetAndDestroy() line 1223 + 30 bytes
CFontStore::RemoveFile(TUid {...}) line 1847
CFontStore::~CFontStore() line 1350
FNTSTR! CFontStore::`vector deleting destructor'(unsigned int) + 60 bytes
QFontDatabaseS60StoreImplementation::~QFontDatabaseS60StoreImplementation() line 135 + 20 bytes
QTGUI! QFontDatabaseS60StoreImplementation::`vector deleting destructor'(unsigned int) + 60 bytes
QFontDatabasePrivate::free() line 626 + 20 bytes
QFontDatabasePrivate::~QFontDatabasePrivate() line 615 + 8 bytes
QTGUI! QFontDatabasePrivate::`vector deleting destructor'(unsigned int) + 60 bytes
QGlobalStaticDeleter<QFontDatabasePrivate>::~QGlobalStaticDeleter() line 1776
__destroy_global_chain() line 83
invokeTable(void (void)* * 0x4a62a1a8 __xp_z, void (void)* * 0x4a62a1a0) line 119
_E32Dll(int 0x00000003) line 63 + 15 bytes
RHandleBase::DoExtendedCloseL() line 1593 + 8 bytes
RHandleBase::DoExtendedClose() line 1572 + 55 bytes
RHandleBase::Close() line 1562
RLibrary::Close() line 272
30ca16af()
30ca1bcb()
main() line 33 + 11 bytes
E32Main() line 74 + 64 bytes
_E32Startup(void * 0x297dfd8c, int 0x00000000) line 83 + 5 bytes
DThread::EpocThreadFunction(void * 0x297dfd8c) line 69 + 22 bytes
NThread::StartThread(void * 0x03dae8d8) line 175 + 12 bytes
KERNEL32! 7c80b729()