Crashes locally i.e. Windows 7 64 bit (2 cores - 2 threads per core) and more frequently on Windows Server 2008 R2 64 bit (8 core - 1 thread per core Xeon) server QtWebkitd is from official build of Qt 5.0.1 (it was more stable with 5.0.0) -- WinDbg says 1 6C1A6276 2 6C1A7BD3 3 6BFF2548 4 6C001B5E 5 6C001312 6 6C0011DD 7 6AEA3693 8 6AEA37FE 9 6AEA37D0 10 6B0765B8 11 6B074BEE 12 6BFB9AEB 13 6BFB71A5 14 6B0D4944 15 6C0B0779 16 6C0A790C 17 6C0A6DD0 18 6BFAC712 19 6BFA9B4B 20 6C00DE28 21 6B72D8CB 22 6B72D399 23 6B72E175 24 6B72DFF3 25 6B443C01 26 6BE17FA2 27 6BA10B44 28 6BA1011C 29 6BA0F0D5 30 6BA0F77B 31 6B443CAB (a60.9fc): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. *** ERROR: Symbol file could not be found. Defaulted to export symbols for Qt5WebKitd.dll - Qt5WebKitd!WTF::randomNumber+0x8b: 6c1a627b c705efbeadbb00000000 mov dword ptr ds:[0BBADBEEFh],0 ds:002b:bbadbeef=???????? -- Disassembly: 6c1a6244 0fb64514 movzx eax,byte ptr [ebp+14h] 6c1a6248 50 push eax 6c1a6249 0fb64d10 movzx ecx,byte ptr [ebp+10h] 6c1a624d 51 push ecx 6c1a624e e83d000000 call Qt5WebKitd!WTF::randomNumber+0xa0 (6c1a6290) 6c1a6253 83c408 add esp,8 6c1a6256 50 push eax 6c1a6257 6800200000 push 2000h 6c1a625c 8b5508 mov edx,dword ptr [ebp+8] 6c1a625f 52 push edx 6c1a6260 6a00 push 0 6c1a6262 ff15e460216c call dword ptr [Qt5WebKitd!WTFLogAlways+0x6ea24 (6c2160e4)] 6c1a6268 8945fc mov dword ptr [ebp-4],eax 6c1a626b 837dfc00 cmp dword ptr [ebp-4],0 6c1a626f 7518 jne Qt5WebKitd!WTF::randomNumber+0x99 (6c1a6289) 6c1a6271 e82a110000 call Qt5WebKitd!WTFReportBacktrace (6c1a73a0) 6c1a6276 e825120000 call Qt5WebKitd!WTFInvokeCrashHook (6c1a74a0) 6c1a627b c705efbeadbb00000000 mov dword ptr ds:[0BBADBEEFh],0 ds:002b:bbadbeef=???????? // Crashes HERE 6c1a6285 33c0 xor eax,eax 6c1a6287 ffd0 call eax 6c1a6289 8b45fc mov eax,dword ptr [ebp-4] 6c1a628c 8be5 mov esp,ebp 6c1a628e 5d pop ebp 6c1a628f c3 ret 6c1a6290 55 push ebp 6c1a6291 8bec mov ebp,esp 6c1a6293 51 push ecx 6c1a6294 0fb6450c movzx eax,byte ptr [ebp+0Ch] 6c1a6298 85c0 test eax,eax 6c1a629a 7413 je Qt5WebKitd!WTF::randomNumber+0xbf (6c1a62af) 6c1a629c 0fb64d08 movzx ecx,byte ptr [ebp+8] 6c1a62a0 f7d9 neg ecx 6c1a62a2 1bc9 sbb ecx,ecx 6c1a62a4 83e120 and ecx,20h -- Qt5Webkitd stack trace Frame nums Function WARNING: Stack unwind information not available. Following frames may be wrong. 00 Qt5WebKitd!WTF::randomNumber+0x8b 01 Qt5WebKitd!WTFLogAlways+0x513 02 Qt5WebKitd!JSC::throwTypeError+0x2c68 03 Qt5WebKitd!JSC::MarkedAllocator::allocateSlowCase+0xace 04 Qt5WebKitd!JSC::MarkedAllocator::allocateSlowCase+0x282 05 Qt5WebKitd!JSC::MarkedAllocator::allocateSlowCase+0x14d 06 Qt5WebKitd!QWebElementCollection::toList+0x2e43 07 Qt5WebKitd!QWebElementCollection::toList+0x2fae 08 Qt5WebKitd!QWebElementCollection::toList+0x2f80 09 Qt5WebKitd!WKVibrationSetProvider+0x16b698 0a Qt5WebKitd!WKVibrationSetProvider+0x169cce 0b Qt5WebKitd!JSC::Structure::get+0x176b 0c Qt5WebKitd!JSC::Structure::addPropertyTransition+0x1d5 0d Qt5WebKitd!WKVibrationSetProvider+0x1c9a24 0e Qt5WebKitd!JSWeakObjectMapClear+0x60719 0f Qt5WebKitd!JSWeakObjectMapClear+0x578ac 10 Qt5WebKitd!JSWeakObjectMapClear+0xc9a6 11 Qt5WebKitd!QtPrintContext::operator=+0xeb2 12 Qt5WebKitd!JSC::Interpreter::getStackTrace+0x205b 13 Qt5WebKitd!JSC::call+0xc8 14 Qt5WebKitd!QWebSettings::handle+0x658ab 15 Qt5WebKitd!QWebSettings::handle+0x65379 16 Qt5WebKitd!QWebSettings::handle+0x66155 17 Qt5WebKitd!QWebSettings::handle+0x65fd3 18 Qt5WebKitd!WTF::MediaTime::timeScale+0x13d91 19 Qt5WebKitd!WTF::MediaTime::isIndefinite+0x459012 1a Qt5WebKitd!WTF::MediaTime::isIndefinite+0x51bb4 1b Qt5WebKitd!WTF::MediaTime::isIndefinite+0x5118c 1c Qt5WebKitd!WTF::MediaTime::isIndefinite+0x50145 1d Qt5WebKitd!WTF::MediaTime::isIndefinite+0x507eb 1e Qt5WebKitd!WTF::MediaTime::timeScale+0x13e3b 1f Qt5WebKitd!WTF::MediaTime::operator delete[]+0x24316 20 Qt5WebKitd!WTF::MediaTime::isIndefinite+0x3b541d 21 Qt5WebKitd!QWebSettings::handle+0x97692 22 Qt5WebKitd!QWebSettings::handle+0x9776b 23 Qt5WebKitd!QWebSettings::handle+0x96be4 24 Qt5WebKitd!QWebSettings::handle+0x977fe 25 Qt5WebKitd!QWebSettings::handle+0x96d57 26 Qt5WebKitd!WTF::MediaTime::isIndefinite+0x39d2ba 27 Qt5WebKitd!WTF::MediaTime::operator delete[]+0x1d65c9 28 Qt5WebKitd!WTF::MediaTime::isIndefinite+0x32f25e 29 Qt5WebKitd!WTF::MediaTime::isIndefinite+0x32f186 2a Qt5WebKitd!WTF::MediaTime::isIndefinite+0x50f5f2 2b Qt5Cored!QTimer::isSingleShot+0x2e7f71 2c Qt5Widgetsd!QGraphicsSceneMouseEvent::QGraphicsSceneMouseEvent+0x33757 2d Qt5Widgetsd!QGraphicsSceneMouseEvent::QGraphicsSceneMouseEvent+0x31193 2e Qt5Cored!QTimer::isSingleShot+0x29e982 2f Qt5Cored!QTimer::isSingleShot+0x2a3d07 30 Qt5Cored!QTimer::isSingleShot+0x329120 31 Qt5Widgetsd!QGraphicsSceneMouseEvent::QGraphicsSceneMouseEvent+0x33757 32 Qt5Widgetsd!QGraphicsSceneMouseEvent::QGraphicsSceneMouseEvent+0x31193 33 Qt5Cored!QTimer::isSingleShot+0x29e982 34 Qt5Cored!QTimer::isSingleShot+0x2a3d07 35 Qt5Cored!QTimer::isSingleShot+0x29f803 36 Qt5Cored!QTimer::isSingleShot+0x29f4bb 37 Qt5Guid!QTransform::fromTranslate+0x3fa16 38 qwindowsd!qt_plugin_query_metadata+0x3693f 39 Qt5Cored!QTimer::isSingleShot+0x326fc5 3a USER32!gapfnScSendMessage+0x332 3b USER32!GetThreadDesktop+0xd7 3c USER32!CharPrevW+0x138 3d USER32!DispatchMessageW+0xf 3e Qt5Cored!QTimer::isSingleShot+0x3280b1 3f qwindowsd!qt_plugin_query_metadata+0x368a9 40 Qt5Cored!QTimer::isSingleShot+0x29b57f 41 Qt5Cored!QTimer::isSingleShot+0x29b6dc 42 Qt5Cored!QTimer::isSingleShot+0x29eebb 43 Qt5Guid!QTransform::fromTranslate+0x569c1 44 Qt5Widgetsd!QGraphicsSceneMouseEvent::QGraphicsSceneMouseEvent+0x30e42 45 fanboy+0x3f99 46 fanboy+0x3552f 47 fanboy+0x3535f 48 KERNEL32!BaseThreadInitThunk+0x12 49 ntdll_77d90000!RtlInitializeExceptionChain+0x63 4a ntdll_77d90000!RtlInitializeExceptionChain+0x36
May be related to this? https://bugs.webkit.org/show_bug.cgi?id=107093