Is a document or a place to find information information on what would cause _objc_msgSend_uncached in a crash report?
more info on the crash
libobjc.A.dylib 0x37e623cc _objc_inform
4 libobjc.A.dylib 0x37e616f2 _ZN7cache_t9bad_cacheEP11objc_objectP13objc_selectorP10objc_class
5 libobjc.A.dylib 0x37e61730 _ZN7cache_t4findEm
6 libobjc.A.dylib 0x37e617da cache_fill
7 libobjc.A.dylib 0x37e65890 lookUpImpOrForward
8 libobjc.A.dylib 0x37e5e02a _class_lookupMethodAndLoadCache3
9 libobjc.A.dylib 0x37e5ddf8 _objc_msgSend_uncached
10 MyApp 0x00253f5c -[AEEngine scanKeyframes:currentFrame:] in AEEngine.m on Line 256
11 MyApp 0x00256148 -[AEEngine doFrame] in AEEngine.m on Line 664
12 MyApp 0x00255f28 __31-[AEEngine doFrameInBackground]_block_invoke in AEEngine.m on Line 642
Got another similar crash that looks like this and ends in cache_t::bad_cache
0 libobjc.A.dylib 0x37b44368 _objc_trap() + 0
1 libobjc.A.dylib 0x37b443c8 _objc_fatal + 68
2 libobjc.A.dylib 0x37b436ee cache_t::bad_cache(objc_object*, objc_selector*, objc_class*) + 202
3 libobjc.A.dylib 0x37b4372c cache_t::find(unsigned long) + 48
4 libobjc.A.dylib 0x37b437d6 cache_fill + 122
5 libobjc.A.dylib 0x37b4788c lookUpImpOrForward + 320
6 libobjc.A.dylib 0x37b40026 _class_lookupMethodAndLoadCache3 + 30
7 libobjc.A.dylib 0x37b3fdf6 _objc_msgSend_uncached + 22
8 MyApp 0x0033811c -[MyCellCell configureCell:] (MyCellCell.m:81)
_objc_msgSend_uncached is an internal implementation detail of objc_msgSend. Crashes in objc_msgSend most often indicate that you're sending a message to a deallocated instance. The most common cause of that is incorrect memory management. The most common cause of incorrect memory management is failure to use ARC.
Most likely, -[AEEngine scanKeyframes:currentFrame:] is trying to message something that is deallocated. That doesn't mean the bug is in AEEngine, only that this is the place you tripped over the over-release. I would start by making sure that ARC is turned on, and that you have addressed all static analyzer warnings.