ios app rejected, need help identifying the issue - ios

Question

Apple rejected my app today, I tried to follow the crash log they sent but I couldn't find the source of the crash, I tested my app on two physical phones:
1- iphone 4
2- iphone 5
and I tested it on xcode simulators:
1-Ipad
2-Ipad Retina
3-Ipad Retina (64-bit)
and it works fine on all of them.
this is what they sent to me
We found that your app crashed on iPad running iOS 7.0.6, which is not in compliance with the App
Store Review Guidelines.
Your app crashed when we:
1) Start the app on a device
2) The app crashes on launch
This occurred when your app was used:
- On Wi-Fi
- On cellular network
and this one of the los they sent to me
Incident Identifier: F0618233-A16F-4782-8B79-3A2AE5D8BFF6
CrashReporter Key: 1db6124687c1282286f546adfc3c54dc0d8ed7ce
Hardware Model: xxx
Process: taptap [266]
Path: /var/mobile/Applications/.....
Identifier: x.x.x
Version: 1.0 (1.0)
Code Type: ARM (Native)
Parent Process: launchd [1]
Date/Time: 2014-02-22 14:32:19.271 -0800
OS Version: iOS 7.0.6 (11B651)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread: 0
Last Exception Backtrace:
(0x2d9bff46 0x3819c6aa 0x2d9bfe88 0x2e347a66 0x8c47c 0x2d982114 0x2d8f6252 0x2e2dbc28 0x301b1f52
0x3019d4c4 0x3013841a 0x3013771c 0x3019cb38 0x325d5708 0x325d52f2 0x2d98a9da 0x2d98a976 0x2d98914a
0x2d8f3c22 0x2d8f3a06 0x3019bdd4 0x30197044 0x8fde2 0x386a4ab2)
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x3875b1fc __pthread_kill + 8
1 libsystem_pthread.dylib 0x387c4a2e pthread_kill + 54
2 libsystem_c.dylib 0x3870bff8 abort + 72
3 libc++abi.dylib 0x37a3acd2 abort_message + 70
4 libc++abi.dylib 0x37a536e0 default_terminate_handler() + 248
5 libobjc.A.dylib 0x3819c91e _objc_terminate() + 190
6 libc++abi.dylib 0x37a511c4 std::__terminate(void (*)()) + 76
7 libc++abi.dylib 0x37a50d28 __cxa_rethrow + 96
8 libobjc.A.dylib 0x3819c7f2 objc_exception_rethrow + 38
9 CoreFoundation 0x2d8f3c98 CFRunLoopRunSpecific + 636
10 CoreFoundation 0x2d8f3a06 CFRunLoopRunInMode + 102
11 UIKit 0x3019bdd4 -[UIApplication _run] + 756
12 UIKit 0x30197044 UIApplicationMain + 1132
13 taptap 0x0008fde2 0x83000 + 52706
14 libdyld.dylib 0x386a4ab4 start + 0
Thread 1 name: Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0 libsystem_kernel.dylib 0x3874883c kevent64 + 24
1 libdispatch.dylib 0x38689210 _dispatch_mgr_invoke + 228
2 libdispatch.dylib 0x38688f96 _dispatch_mgr_thread$VARIANT$mp + 34
Thread 2:
0 libsystem_kernel.dylib 0x3875bc7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x387c1dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x387c1c80 start_wqthread + 4
Thread 3:
0 libsystem_kernel.dylib 0x3875bc7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x387c1dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x387c1c80 start_wqthread + 4
Thread 4 name: WebThread
Thread 4:
0 libsystem_kernel.dylib 0x3875afa8 __psynch_mutexwait + 24
1 libsystem_pthread.dylib 0x387c1f0a _pthread_mutex_lock + 302
2 WebCore 0x35a6f7f0 _WebTryThreadLock(bool) + 104
3 WebCore 0x35a6f772 WebRunLoopLock(__CFRunLoopObserver*, unsigned long,
void*) + 42
4 CoreFoundation 0x2d98b1ca
__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 18
5 CoreFoundation 0x2d988b6c __CFRunLoopDoObservers + 280
6 CoreFoundation 0x2d988f7c __CFRunLoopRun + 932
7 CoreFoundation 0x2d8f3c22 CFRunLoopRunSpecific + 518
8 CoreFoundation 0x2d8f3a06 CFRunLoopRunInMode + 102
9 WebCore 0x35a6e266 RunWebThread(void*) + 414
10 libsystem_pthread.dylib 0x387c3c1a _pthread_body + 138
11 libsystem_pthread.dylib 0x387c3b8a _pthread_start + 98
12 libsystem_pthread.dylib 0x387c1c8c thread_start + 4
Thread 5:
0 libsystem_kernel.dylib 0x38748a8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x38748888 mach_msg + 44
2 CoreFoundation 0x2d98a7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x2d988ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x2d8f3c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x2d8f3a06 CFRunLoopRunInMode + 102
6 libAVFAudio.dylib 0x2c976584 GenericRunLoopThread::Entry(void*) + 124
7 libAVFAudio.dylib 0x2c96a99c CAPThread::Entry(CAPThread*) + 176
8 libsystem_pthread.dylib 0x387c3c1a _pthread_body + 138
9 libsystem_pthread.dylib 0x387c3b8a _pthread_start + 98
10 libsystem_pthread.dylib 0x387c1c8c thread_start + 4
Thread 6:
0 libsystem_kernel.dylib 0x3875bc7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x387c1dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x387c1c80 start_wqthread + 4
Thread 7 name: com.apple.NSURLConnectionLoader
Thread 7:
0 libsystem_kernel.dylib 0x38748a8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x38748888 mach_msg + 44
2 CoreFoundation 0x2d98a7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x2d988ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x2d8f3c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x2d8f3a06 CFRunLoopRunInMode + 102
6 Foundation 0x2e32e2f2 +[NSURLConnection(Loader) _resourceLoadLoop:] + 314
7 Foundation 0x2e3a3c82 __NSThread__main__ + 1058
8 libsystem_pthread.dylib 0x387c3c1a _pthread_body + 138
9 libsystem_pthread.dylib 0x387c3b8a _pthread_start + 98
10 libsystem_pthread.dylib 0x387c1c8c thread_start + 4
Thread 8 name: com.apple.CFSocket.private
Thread 8:
0 libsystem_kernel.dylib 0x3875b440 __select + 20
1 CoreFoundation 0x2d98e680 __CFSocketManager + 480
2 libsystem_pthread.dylib 0x387c3c1a _pthread_body + 138
3 libsystem_pthread.dylib 0x387c3b8a _pthread_start + 98
4 libsystem_pthread.dylib 0x387c1c8c thread_start + 4
Thread 0 crashed with ARM Thread State (32-bit):
r0: 0x00000000 r1: 0x00000000 r2: 0x00000000 r3: 0x00002060
r4: 0x00000006 r5: 0x3a60618c r6: 0x00000000 r7: 0x27d80594
r8: 0x1451e760 r9: 0x00000001 r10: 0x00000000 r11: 0x403e0000
ip: 0x00000148 sp: 0x27d80588 lr: 0x387c4a33 pc: 0x3875b1fc
cpsr: 0x00000010
how could I get to the cause of this crash log, thanks

Answer 1

That Apple isn't providing the Binary Images section in the provided crash report makes it much harder than necessary to find out what the cause is. Without the that information it is not possible to symbolicate the Last Exception Backtrace and find out more automatically.
The reason for the crash is definitely an exception inside the app, it is not because the apps main thread was blocking for too long because in that case the report would not show a Last Exception Backtrace and look very different. But using synchronous networking requests on the main thread should never be done anyway!
So how to find out more about this exception. Since the Binary Images are missing and the symbols for the system calls are already symbolicated, it is hard to find the address ranges for each system framework. But we know the load address from the app looking at the following line:
13 taptap 0x0008fde2 0x83000 + 52706
So the load address is 0x83000. Now we take the Last Exception Backtrace addresses and search for the ones that are likely belonging to the app:
0x2d9bff46 0x3819c6aa 0x2d9bfe88 0x2e347a66 0x8c47c 0x2d982114 0x2d8f6252 0x2e2dbc28 0x301b1f52
0x3019d4c4 0x3013841a 0x3013771c 0x3019cb38 0x325d5708 0x325d52f2 0x2d98a9da 0x2d98a976 0x2d98914a
0x2d8f3c22 0x2d8f3a06 0x3019bdd4 0x30197044 0x8fde2 0x386a4ab2
The ones that should belong to the app are the following:
0x8c47c 0x8fde2
0x8fde2 is the same as in the main thread and will symbolicate to something like
13 taptap 0x0008fde2 main (main.m:14)
The interesting one is 0x8c47c, which shows up 5th place from top from the exception. To get the symbol for this one, you need the apps dSYM that you submitted to Apple. You'll find it in the organizer Archives tab. Select the app and choose the entry for the app. Right mouse click the item that you used to submit to Apple and choose Show in Finder. Then another right mouse click and choose Show Package Contents. Open the dSYMs folder.
It is unknown which iPad was used and since the Binary Images section is missing we don't know it either (which would show the used architecture and UUID to verify the architecture, binary, and dSYM). So it can be either armv7 or armv7s. The newest iPad mini with retina and the iPad Air use armv7s in 32 bit mode, all other iPads also either use armv7s or armv7. So we have to try both which may return the same results.
Now open a terminal window and type:
`xcrun atos -arch armv7s -l 0x83000 DragInTheDSYMItemFromTheFinderInHere 0x8c47c`
Then use the same if it doesn't make sense and replace armv7s with armv7.
This should give you the class, method, filename and line number where the exception occured in your app. We'll still be missing the exception reason since the crash report doesn't show that and due to missing binary images we can't really symbolicate all the other addresses and use that find out more. Hopefully this will already give an idea.
Once you have that, please update your question with the details.
UPDATE: Now that the binary images where provided, I was able to symbolicate the crash report and get the Last Exception Backtrace symbols. Although without the app symbols, since I obviously don't have the dSYM.
The symbolicated report is available here: http://pastebin.com/An10dUpi
The important frames are the following
Last Exception Backtrace:
0 CoreFoundation 0x2d9bff46 __exceptionPreprocess + 126
1 libobjc.A.dylib 0x3819c6aa objc_exception_throw + 32
2 CoreFoundation 0x2d9bfe88 +[NSException raise:format:] + 98
3 Foundation 0x2e347a66 +[NSJSONSerialization JSONObjectWithData:options:error:] + 60
4 taptap 0x8c47c 0x83000 + 38012
This shows that the crash occurs because the app tries to serialize a given NSData object into json and fails to do so, because the NSData object is not a valid json string.
When symbolicating the 4th line as described above in the post, you will get the exact line in your code where this happens.