Creator crashes in Designer mode

Process:               Qt Creator [1083]
Path:                  /Users/USER/*/Qt Creator.app/Contents/MacOS/Qt Creator
Identifier:            org.qt-project.qtcreator
Version:               3.3.0 (3.3.0)
Code Type:             X86-64 (Native)
Parent Process:        ??? [1]
Responsible:           Qt Creator [1083]
User ID:               501

Date/Time:             2015-04-22 19:47:46.272 +0200
OS Version:            Mac OS X 10.10.3 (14D136)
Report Version:        11
Anonymous UUID:        29C99AA7-FDBA-6CC4-FB6E-09B613435045

Sleep/Wake UUID:       0658DDCF-8D86-4BAB-AC54-5D95F1BB1DA7

Time Awake Since Boot: 150000 seconds
Time Since Wake:       34000 seconds

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000000000008

VM Regions Near 0x8:
--> 
    __TEXT                 00000001032a4000-00000001032b7000 [   76K] r-x/rwx SM=COW  /Users/USER/*/Qt Creator.app/Contents/MacOS/Qt Creator

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   org.qt-project.QtCore         	0x0000000104299f95 QCoreApplication::notifyInternal(QObject*, QEvent*) + 85
1   org.qt-project.QtGui          	0x0000000103b28195 QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) + 1605
2   org.qt-project.QtGui          	0x0000000103b1551a QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 346
3   libqcocoa.dylib               	0x00000001063cca41 0x1063ab000 + 137793
4   com.apple.CoreFoundation      	0x00007fff8dcf6a01 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
5   com.apple.CoreFoundation      	0x00007fff8dce8b8d __CFRunLoopDoSources0 + 269
6   com.apple.CoreFoundation      	0x00007fff8dce81bf __CFRunLoopRun + 927
7   com.apple.CoreFoundation      	0x00007fff8dce7bd8 CFRunLoopRunSpecific + 296
8   com.apple.HIToolbox           	0x00007fff8c25956f RunCurrentEventLoopInMode + 235
9   com.apple.HIToolbox           	0x00007fff8c2591ee ReceiveNextEventCommon + 179
10  com.apple.HIToolbox           	0x00007fff8c25912b _BlockUntilNextEventMatchingListInModeWithFilter + 71
11  com.apple.AppKit              	0x00007fff900059bb _DPSNextEvent + 978
12  com.apple.AppKit              	0x00007fff90004f68 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 346
13  com.apple.AppKit              	0x00007fff8fffabf3 -[NSApplication run] + 594
14  libqcocoa.dylib               	0x00000001063cb92d 0x1063ab000 + 133421
15  org.qt-project.QtCore         	0x00000001042975ad QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 381
16  org.qt-project.QtCore         	0x000000010429a58a QCoreApplication::exec() + 346
17  org.qt-project.qtcreator      	0x00000001032b16b7 main + 22103
18  org.qt-project.qtcreator      	0x00000001032a93a4 start + 52