#0
Crashed: com.apple.main-thread
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x00000001625fbeb8
0
libobjc.A.dylib 
objc_msgSend + 16
1   CoreFoundation  
__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 20
2   CoreFoundation  
_CFXNotificationPost + 2060
3
Foundation  
-[NSNotificationCenter postNotificationName:object:userInfo:] + 72
The bug occurred infrequently.So It's too hard for me to find out why. From the infomation I know It's occurred after a postNotification,but I found all the places where receive the notification and i write this in dealloc "[[NSNotificationCenter defaultCenter] removeObserver:self]". Does anyone know any other possibility?