App Crash, no idea why - iphone

Question

I trying to figure out why my App crashes sometimes on costumers devices. It doesnt matter if the device is jailbreaked or not. My App is from the AppStore. The other crashlogs are nearly the same although their crashed threads are different.
Hardware Model: iPhone3,1
Process: [the APP] [296]
Path: /var/mobile/Applications/06DF5BC5-F9C2-49EE-B2D5-5979C09B51A2/[the APP].app/[the APP]
Identifier: [the APP]
Version: 3.3.0
Code Type: ARM
Parent Process: launchd [1]
Date/Time: 2012-07-22 15:15:18 +0000
OS Version: iPhone OS 5.1.1 (9B206)
Report Version: 104
Exception Type: SIGSEGV
Exception Codes: SEGV_ACCERR at 0xbbadbeef
Crashed Thread: 7
Thread 0:
0 libsystem_kernel.dylib 0x35c39004 mach_msg_trap + 20
1 CoreFoundation 0x353673f3 __CFRunLoopServiceMachPort + 127
2 CoreFoundation 0x353660f1 __CFRunLoopRun + 825
3 CoreFoundation 0x352e94a5 CFRunLoopRunSpecific + 301
4 CoreFoundation 0x352e936d CFRunLoopRunInMode + 105
5 GraphicsServices 0x36f85439 GSEventRunModal + 137
6 UIKit 0x32df5cd5 UIApplicationMain + 1081
7 [the APP] 0x0000b549 main (main.m:20)
Thread 1:
0 libsystem_kernel.dylib 0x35c393a8 kevent + 24
1 libdispatch.dylib 0x3422cbc9 _dispatch_mgr_wakeup + 1
Thread 2:
0 libsystem_kernel.dylib 0x35c490d8 __psynch_mutexwait + 24
1 WebCore 0x311454ef _ZL17_WebTryThreadLockb + 215
2 WebCore 0x311a4173 _ZL19SendDelegateMessageP12NSInvocation + 707
3 WebKit 0x3507ad87 -[_WebSafeForwarder forwardInvocation:] + 119
4 CoreFoundation 0x35395a83 ___forwarding___ + 667
5 CoreFoundation 0x352f0650 _CF_forwarding_prep_0 + 48
6 WebKit 0x350816a1 WebFrameLoaderClient::dispatchDecidePolicyForNavigationAction(void (WebCore::PolicyChecker::*)(WebCore::PolicyAction), WebCore::NavigationAction const&, WebCore::ResourceRequest const&, WTF::PassRefPtr) + 221
7 WebCore 0x3120b8b9 WebCore::PolicyChecker::checkNavigationPolicy(WebCore::ResourceRequest const&, WebCore::DocumentLoader*, WTF::PassRefPtr, void (*)(void*, WebCore::ResourceRequest const&, WTF::PassRefPtr, bool), void*) + 873
8 WebCore 0x3120ae4d WebCore::FrameLoader::loadWithDocumentLoader(WebCore::DocumentLoader*, WebCore::FrameLoadType, WTF::PassRefPtr) + 913
9 WebCore 0x312092b9 WebCore::FrameLoader::load(WebCore::DocumentLoader*) + 169
10 WebCore 0x312091e5 WebCore::FrameLoader::load(WebCore::ResourceRequest const&, WebCore::SubstituteData const&, bool) + 241
11 WebKit 0x350b3f5f -[WebFrame _loadData:MIMEType:textEncodingName:baseURL:unreachableURL:] + 1119
12 WebKit 0x350b3797 -[WebFrame _loadHTMLString:baseURL:unreachableURL:] + 79
13 WebKit 0x350b37bb -[WebFrame loadHTMLString:baseURL:] + 31
14 WebCore 0x311950b5 HandleRunSource + 365
15 CoreFoundation 0x35367ad3 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
16 CoreFoundation 0x35367335 __CFRunLoopDoSources0 + 365
17 CoreFoundation 0x35366045 __CFRunLoopRun + 653
18 CoreFoundation 0x352e94a5 CFRunLoopRunSpecific + 301
19 CoreFoundation 0x352e936d CFRunLoopRunInMode + 105
20 WebCore 0x311e8ca3 _ZL12RunWebThreadPv + 403
21 libsystem_c.dylib 0x32756735 _pthread_start + 321
Thread 3:
0 libsystem_kernel.dylib 0x35c39004 mach_msg_trap + 20
1 CoreFoundation 0x353673f3 __CFRunLoopServiceMachPort + 127
2 CoreFoundation 0x3536612b __CFRunLoopRun + 883
3 CoreFoundation 0x352e94a5 CFRunLoopRunSpecific + 301
4 CoreFoundation 0x352e936d CFRunLoopRunInMode + 105
5 Foundation 0x34e22bb9 +[NSURLConnection(Loader) _resourceLoadLoop:] + 309
6 Foundation 0x34e22a81 -[NSThread main] + 73
7 Foundation 0x34eb6591 __NSThread__main__ + 1049
8 libsystem_c.dylib 0x32756735 _pthread_start + 321
Thread 4:
0 libsystem_kernel.dylib 0x35c49570 __select + 20
1 libsystem_c.dylib 0x32756735 _pthread_start + 321
Thread 5:
0 libsystem_kernel.dylib 0x35c39004 mach_msg_trap + 20
1 CoreFoundation 0x353673f3 __CFRunLoopServiceMachPort + 127
2 CoreFoundation 0x3536612b __CFRunLoopRun + 883
3 CoreFoundation 0x352e94a5 CFRunLoopRunSpecific + 301
4 CoreFoundation 0x352e936d CFRunLoopRunInMode + 105
5 YouTube 0x33e336c9 -[YTImageLoader(Internal) _startLoader] + 245
6 Foundation 0x34e22a81 -[NSThread main] + 73
7 Foundation 0x34eb6591 __NSThread__main__ + 1049
8 libsystem_c.dylib 0x32756735 _pthread_start + 321
Thread 6:
0 libsystem_kernel.dylib 0x35c49cd4 __workq_kernreturn + 8
Thread 7 Crashed:
0 WebCore 0x311454e2 _ZL17_WebTryThreadLockb + 202
1 WebCore 0x3114540f WebThreadLock + 55
2 UIKit 0x32e5537b -[UIWebTiledView layoutSubviews] + 43
3 UIKit 0x32e5534b -[UIWebDocumentView layoutSubviews] + 127
4 UIKit 0x32dcaf37 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 183
5 CoreFoundation 0x352f21fb -[NSObject performSelector:withObject:] + 43
6 QuartzCore 0x321c2aa5 -[CALayer layoutSublayers] + 217
7 QuartzCore 0x321c26bd CA::Layer::layout_if_needed(CA::Transaction*) + 217
8 QuartzCore 0x321c6843 CA::Context::commit_transaction(CA::Transaction*) + 227
9 QuartzCore 0x321c657f CA::Transaction::commit() + 315
10 QuartzCore 0x3220dd01 CA::Transaction::release_thread(void*) + 37
11 libsystem_c.dylib 0x327490ff _pthread_tsd_cleanup + 171
12 libsystem_c.dylib 0x32748d7b _pthread_exit + 123
13 libsystem_c.dylib 0x3275a0f3 pthread_exit + 31
14 Foundation 0x34e3237b +[NSThread exit] + 11
15 Foundation 0x34eb65af __NSThread__main__ + 1079
16 libsystem_c.dylib 0x32756735 _pthread_start + 321
Thread 8:
0 libsystem_kernel.dylib 0x35c49cd4 __workq_kernreturn + 8
Thread 9:
0 libsystem_kernel.dylib 0x35c49cd4 __workq_kernreturn + 8
Thread 10:
0 libsystem_kernel.dylib 0x35c49cd4 __workq_kernreturn + 8
Thread 11:
0 libsystem_kernel.dylib 0x35c49cd4 __workq_kernreturn + 8
Thread 7 crashed with ARM Thread State:
r0: 0xffffffff r1: 0x00001100 r2: 0x2ffc850c r3: 0x00000000
r4: 0xbbadbeef r5: 0x00000000 r6: 0x0054b000 r7: 0x2ffc8b4c
r8: 0x0ca32800 r9: 0x3399fc2c r10: 0x2ffc8be4 r11: 0x2ffc8ebc
ip: 0x3ee8e270 sp: 0x2ffc8b40 lr: 0x35790fef pc: 0x32c7f4e2
cpsr: 0x60000030
Binary Images:
[cut cause of char limit]
I have no idea what happend, anyone an idea?

Answer 1

The problem is that you send messages to UI objects from a background thread, which is forbidden.
Thread 7 crashed with a stack trace into UIView's layout mechanism. The fact that thread 7 is in this code probably results from a setNeedsLayout or some other method being sent from this background thread.

Answer 2

I think web view finished loading and trying to reload view but view controller was poped and released,you need to add this in viewWillDisappear method:
- (void)viewWillDisappear:(BOOL)animated{
[super viewWillDisappear:animated];
if ([webView isLoading]) {
[webView stopLoading];
}
}

Answer 3

The project that I am on sees a similar exception for a WinTel based GWT App running on the WebKit. It has been determined that this particular problem only occurs when the WebKit runs out of memory.