This crash happens intermittently. I have a 2nd screen attached to my notebook. Creator is usually open on the 2nd screen. The crash, if it happens, always happens upon wake up from sleep. When waking up the 2nd monitor may not be ready yet (OS X may not see it right away). I can't reproduce it yet, unfortunately. The system is otherwise stable. Looks like an access to deleted screen, thus I'm filing it under Qt, not under Creator.

Process: Qt Creator [13510]
Path: /Users/USER/*/Qt Creator.app/Contents/MacOS/Qt Creator
Identifier: org.qt-project.qtcreator
Version: 2.8.1 (2.8.1)
Code Type: X86-64 (Native)
Parent Process: launchd [142]
User ID: 501

Date/Time: 2013-10-01 07:52:19.216 -0400
OS Version: Mac OS X 10.8.5 (12F37)
Report Version: 10
Sleep/Wake UUID: 4A5C2EEF-D140-4D95-BBB9-BC01AC31F09B

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

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000

VM Regions Near 0:
-->
__TEXT 0000000100000000-0000000100013000 [ 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 QtGui 0x00000001006374e8 QPlatformScreen::screen() const + 8
1 libqcocoa.dylib 0x0000000103b344aa 0x103b25000 + 62634
2 com.apple.CoreFoundation 0x00007fff97d7feda _CFXNotificationPost + 2554
3 com.apple.Foundation 0x00007fff97a1b7b6 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
4 com.apple.AppKit 0x00007fff8ffa4922 -[NSWindow _screenChanged:] + 60
5 com.apple.AppKit 0x00007fff8ffa509e -[NSWindow _displayChangedDepth] + 19
6 com.apple.AppKit 0x00007fff8ffa511c -[NSWindow _displayChanged] + 122
7 com.apple.AppKit 0x00007fff8f9cf7fa -[NSApplication makeWindowsPerform:inOrder:] + 404
8 com.apple.AppKit 0x00007fff8fc1e914 -[NSApplication _reactToDisplayChanged:resetScreens:] + 107
9 com.apple.AppKit 0x00007fff8fab474c -[NSApplication sendEvent:] + 6025
10 libqcocoa.dylib 0x0000000103b3ef71 0x103b25000 + 106353
11 com.apple.AppKit 0x00007fff8f9ca21a -[NSApplication run] + 636
12 libqcocoa.dylib 0x0000000103b3b98b 0x103b25000 + 92555
13 QtCore 0x0000000100c1c753 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 403
14 QtCore 0x0000000100c1f845 QCoreApplication::exec() + 357
15 org.qt-project.qtcreator 0x000000010000c523 main + 20563
16 org.qt-project.qtcreator 0x00000001000047b4 start + 52