App crashes on iPhone 5 with iOS 6 - iphone

Question

The resolution center rejected my app because, as they say, it crashes on iPhone 5 with iOS 6.1.2.
I have an iPhone 4 with iOS 6.1.2 and it doesnt crash. I can't solve that problem!
They also wrote that the app crash when:
Launch the app
Login with Facebook.
App crashes when the device returns to the app.
Here the simbolicated crash log:
Last Exception Backtrace:
0 CoreFoundation 0x344ec3e2 0x3442a000 + 795618
1 libobjc.A.dylib 0x3c1dd95e 0x3c1d5000 + 35166
2 CoreFoundation 0x344eff2c 0x3442a000 + 810796
3 CoreFoundation 0x344ee648 0x3442a000 + 804424
4 CoreFoundation 0x34446204 0x3442a000 + 115204
5 Kick - Serie A 0x0007252c -[LetturaScrittura writeStringToFile:] (LetturaScrittura.m:26)
6 Kick - Serie A 0x0006e9da __25-[Profilo carica_profilo]_block_invoke (Profilo.m:314)
7 Kick - Serie A 0x0007e14a -[FBRequestConnection completeWithResults:orError:] (FBRequestConnection.m:1200)
8 Kick - Serie A 0x0007d56c -[FBRequestConnection completeWithResponse:data:orError:] (FBRequestConnection.m:983)
9 Kick - Serie A 0x0007b6aa __68-[FBRequestConnection startWithCacheIdentity:skipRoundtripIfCached:]_block_invoke_0 (FBRequestConnection.m:499)
10 Kick - Serie A 0x0007f38e -[FBURLConnection invokeHandler:error:response:responseData:] (FBURLConnection.m:163)
11 Kick - Serie A 0x0007f8f4 -[FBURLConnection connectionDidFinishLoading:] (FBURLConnection.m:233)
12 Foundation 0x34e28910 0x34d53000 + 874768
13 Foundation 0x34d68764 0x34d53000 + 87908
14 Foundation 0x34d68680 0x34d53000 + 87680
15 CFNetwork 0x341c964a 0x34141000 + 558666
16 CFNetwork 0x341c8d2e 0x34141000 + 556334
17 CFNetwork 0x341f100e 0x34141000 + 720910
18 CoreFoundation 0x34432ac8 0x3442a000 + 35528
19 CFNetwork 0x341f146e 0x34141000 + 722030
20 CFNetwork 0x3415545c 0x34141000 + 83036
21 CoreFoundation 0x344c18f2 0x3442a000 + 620786
22 CoreFoundation 0x344c1158 0x3442a000 + 618840
23 CoreFoundation 0x344bff2a 0x3442a000 + 614186
24 CoreFoundation 0x34433238 0x3442a000 + 37432
25 CoreFoundation 0x344330c4 0x3442a000 + 37060
26 GraphicsServices 0x38011336 0x3800c000 + 21302
27 UIKit 0x3634f2b4 0x362f8000 + 357044
28 Kick - Serie A 0x0006ac92 main (main.m:16)
29 libdyld.dylib 0x3c60ab1c 0x3c609000 + 6940
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x3c6d1350 __pthread_kill + 8
1 libsystem_c.dylib 0x3c647fb2 pthread_kill + 54
2 libsystem_c.dylib 0x3c684366 abort + 90
3 libc++abi.dylib 0x3bc2cdda abort_message + 70
4 libc++abi.dylib 0x3bc2a094 default_terminate() + 20
5 libobjc.A.dylib 0x3c1dda58 _objc_terminate() + 144
6 libc++abi.dylib 0x3bc2a118 safe_handler_caller(void (*)()) + 76
7 libc++abi.dylib 0x3bc2a1b0 std::terminate() + 16
8 libc++abi.dylib 0x3bc2b626 __cxa_rethrow + 90
9 libobjc.A.dylib 0x3c1dd9b0 objc_exception_rethrow + 8
10 CoreFoundation 0x3443329c CFRunLoopRunSpecific + 452
11 CoreFoundation 0x344330c4 CFRunLoopRunInMode + 100
12 GraphicsServices 0x38011336 GSEventRunModal + 70
13 UIKit 0x3634f2b4 UIApplicationMain + 1116
14 Kick - Serie A 0x0006ac92 main (main.m:16)
15 libdyld.dylib 0x3c60ab1c start + 0
Thread 1 name: Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0 libsystem_kernel.dylib 0x3c6c15d0 kevent64 + 24
1 libdispatch.dylib 0x3c5fcd22 _dispatch_mgr_invoke + 806
2 libdispatch.dylib 0x3c5f8374 _dispatch_mgr_thread + 32
Thread 2 name: WebThread
Thread 2:
0 libsystem_kernel.dylib 0x3c6c0e30 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3c6c0fd0 mach_msg + 48
2 CoreFoundation 0x344c12b6 __CFRunLoopServiceMachPort + 126
3 CoreFoundation 0x344c002c __CFRunLoopRun + 900
4 CoreFoundation 0x34433238 CFRunLoopRunSpecific + 352
5 CoreFoundation 0x344330c4 CFRunLoopRunInMode + 100
6 WebCore 0x3a432390 RunWebThread(void*) + 440
7 libsystem_c.dylib 0x3c62a0de _pthread_start + 306
8 libsystem_c.dylib 0x3c629fa4 thread_start + 4
Thread 3 name: com.apple.NSURLConnectionLoader
Thread 3:
0 libsystem_kernel.dylib 0x3c6c0e30 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3c6c0fd0 mach_msg + 48
2 CoreFoundation 0x344c12b6 __CFRunLoopServiceMachPort + 126
3 CoreFoundation 0x344c002c __CFRunLoopRun + 900
4 CoreFoundation 0x34433238 CFRunLoopRunSpecific + 352
5 CoreFoundation 0x344330c4 CFRunLoopRunInMode + 100
6 Foundation 0x34d80888 +[NSURLConnection(Loader) _resourceLoadLoop:] + 304
7 Foundation 0x34e0422c __NSThread__main__ + 968
8 libsystem_c.dylib 0x3c62a0de _pthread_start + 306
9 libsystem_c.dylib 0x3c629fa4 thread_start + 4
Thread 4 name: com.apple.CFSocket.private
Thread 4:
0 libsystem_kernel.dylib 0x3c6d1594 __select + 20
1 CoreFoundation 0x344c5474 __CFSocketManager + 676
2 libsystem_c.dylib 0x3c62a0de _pthread_start + 306
3 libsystem_c.dylib 0x3c629fa4 thread_start + 4
Thread 5:
0 libsystem_kernel.dylib 0x3c6d1d98 __workq_kernreturn + 8
1 libsystem_c.dylib 0x3c61fad6 _pthread_workq_return + 14
2 libsystem_c.dylib 0x3c61f7f2 _pthread_wqthread + 362
3 libsystem_c.dylib 0x3c61f680 start_wqthread + 4
Thread 6:
0 libsystem_kernel.dylib 0x3c6d1d98 __workq_kernreturn + 8
1 libsystem_c.dylib 0x3c61fad6 _pthread_workq_return + 14
2 libsystem_c.dylib 0x3c61f7f2 _pthread_wqthread + 362
3 libsystem_c.dylib 0x3c61f680 start_wqthread + 4
Thread 0 crashed with ARM Thread State (32-bit):
r0: 0x00000000 r1: 0x00000000 r2: 0x00000000 r3: 0x3e191524
r4: 0x00000006 r5: 0x3e191b78 r6: 0x1dd85ca4 r7: 0x2fd979f4
r8: 0x1dd85c80 r9: 0x00000300 r10: 0x00000000 r11: 0x3455b022
ip: 0x00000148 sp: 0x2fd979e8 lr: 0x3c647fb7 pc: 0x3c6d1350
cpsr: 0x00000010
Here's the LetturaScrittore method that makes the app crash (I use it to write on a .txt the email of the facebook user):
- (void)writeStringToFile:(NSString*)aString {
// Build the path, and create if needed.
NSString* filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* fileName = #"myTextFile.txt";
NSString* fileAtPath = [filePath stringByAppendingPathComponent:fileName];
if (![[NSFileManager defaultManager] fileExistsAtPath:fileAtPath]) {
[[NSFileManager defaultManager] createFileAtPath:fileAtPath contents:nil attributes:nil];
}
// The main act.
[[aString dataUsingEncoding:NSUTF8StringEncoding] writeToFile:fileAtPath atomically:YES];
}

Answer 1

The reason for the crash is that you don't actually pass a NSString object to writeStringToFile.

Answer 2

My mistake was on the facebook auth login: without the permission of the email, facebook return nothing, and the app crashes when trying to write the .txt file.