@leonieDF:
There is nothing obvious in the Console, except that it says that a crash log has been written.
These are the first 50 lines of the crash log:
Process: Aperture [329]
Path: /Applications/Aperture.app/Contents/MacOS/Aperture
Identifier: com.apple.Aperture
Version: 3.4 (3.4)
Build Info: Aperture-301036000000000~2
App Item ID: 408981426
App External ID: 10581304
Code Type: X86-64 (Native)
Parent Process: launchd [165]
User ID: 502
Date/Time: 2012-09-20 15:46:40.680 +0300
OS Version: Mac OS X 10.8.2 (12C54)
Report Version: 10
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 000000010cde9000-000000010d53b000 [ 7496K] r-x/rwx SM=COW /Applications/Aperture.app/Contents/MacOS/Aperture
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 com.apple.CoreFoundation 0x000000010f02792b CFRelease + 379
1 com.apple.CoreFoundation 0x000000010f0bea12 CFURLCreateFileReferenceURL + 850
2 com.apple.CoreFoundation 0x000000010f0e66d6 -[NSURL fileReferenceURL] + 102
3 com.apple.Foundation 0x00000001111312dd -[NSFileManager componentsToDisplayForPath:] + 102
4 com.apple.RedRock 0x000000010dafc13e +[RKImageCaptureManager defaultImageCaptureApplicationPathAndAllCandidateApplications:] + 371
5 com.apple.Aperture 0x000000010ce448b5 0x10cde9000 + 374965
6 com.apple.CoreFoundation 0x000000010f06447a _CFXNotificationPost + 2554
7 com.apple.Foundation 0x000000011106d846 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
8 com.apple.AppKit 0x0000000111c5060d -[NSApplication _postDidFinishNotification] + 292
9 com.apple.AppKit 0x0000000111c50346 -[NSApplication _sendFinishLaunchingNotification] + 216
10 com.apple.AppKit 0x0000000111c4d532 -[NSApplication(NSAppleEventHandling) _handleAEOpenEvent:] + 566
11 com.apple.AppKit 0x0000000111c4d12c -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] + 351
12 com.apple.Foundation 0x000000011108712b -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] + 308
13 com.apple.Foundation 0x0000000111086f8d _NSAppleEventManagerGenericHandler + 106
14 com.apple.AE 0x0000000114ee4b48 aeDispatchAppleEvent(AEDesc const*, AEDesc*, unsigned int, unsigned char*) + 307
15 com.apple.AE 0x0000000114ee49a9 dispatchEventAndSendReply(AEDesc const*, AEDesc*) + 37
16 com.apple.AE 0x0000000114ee4869 aeProcessAppleEvent + 318
17 com.apple.HIToolbox 0x000000011313a8e9 AEProcessAppleEvent + 100
18 com.apple.AppKit 0x0000000111c49916 _DPSNextEvent + 1456
19 com.apple.AppKit 0x0000000111c48ed2 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
20 com.apple.Aperture 0x000000010d25d00d 0x10cde9000 + 4669453
21 com.apple.AppKit 0x0000000111c40283 -[NSApplication run] + 517
22 com.apple.prokit 0x000000010f95d324 NSProApplicationMain + 378
23 com.apple.Aperture 0x000000010cdf89c2 0x10cde9000 + 63938
24 com.apple.Aperture 0x000000010cdf8314 0x10cde9000 + 62228