我们有一个在iOS 7.x上运行的iPad应用程序，它已经崩溃了以下日志：
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread: 0
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x3aef11fc __pthread_kill + 8
1 libsystem_pthread.dylib 0x3af5aa2e pthread_kill + 54
2 libsystem_c.dylib 0x3aea1ff8 abort + 72
3 libsystem_c.dylib 0x3ae81d22 __assert_rtn + 178
4 BLSOffline 0x007c066c 0x6c000 + 7685740
5 BLSOffline 0x007c06da 0x6c000 + 7685850
6 BLSOffline 0x0068e7b8 0x6c000 + 6432696
7 BLSOffline 0x0069609c 0x6c000 + 6463644
8 BLSOffline 0x000cda50 0x6c000 + 399952
9 BLSOffline 0x000be39a 0x6c000 + 336794
10 BLSOffline 0x000acd6e 0x6c000 + 265582
11 UIKit 0x32b05a56 -[UITableView _createPreparedCellForGlobalRow:withIndexPath:] + 406
12 UIKit 0x32aade78 -[UITableView _updateVisibleCellsNow:] + 1800
13 UIKit 0x32aad694 -[UITableView layoutSubviews] + 180
14 UIKit 0x329d3d9e -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 342
15 QuartzCore 0x3265ac66 -[CALayer layoutSublayers] + 138
16 QuartzCore 0x32656476 CA::Layer::layout_if_needed(CA::Transaction*) + 346
17 QuartzCore 0x32656308 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 12
18 QuartzCore 0x32655d1a CA::Context::commit_transaction(CA::Transaction*) + 226
19 QuartzCore 0x32655b2a CA::Transaction::commit() + 310
20 QuartzCore 0x3264f858 CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 52
21 CoreFoundation 0x3022c1ca __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 18
22 CoreFoundation 0x30229b6c __CFRunLoopDoObservers + 280
23 CoreFoundation 0x30229eae __CFRunLoopRun + 726
24 CoreFoundation 0x30194c22 CFRunLoopRunSpecific + 518
25 CoreFoundation 0x30194a06 CFRunLoopRunInMode + 102
26 GraphicsServices 0x34e6827e GSEventRunModal + 134
27 UIKit 0x32a38044 UIApplicationMain + 1132
28 BLSOffline 0x00096cb6 0x6c000 + 175286
29 libdyld.dylib 0x3ae3aab4 start + 0
Thread 1:
0 libsystem_kernel.dylib 0x3aede83c kevent64 + 24
1 libdispatch.dylib 0x3ae1f210 _dispatch_mgr_invoke + 228
2 libdispatch.dylib 0x3ae1ef96 _dispatch_mgr_thread$VARIANT$mp + 34
Thread 2 name: WebThread
Thread 2:
0 libsystem_kernel.dylib 0x3aedea8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3aede888 mach_msg + 44
2 CoreFoundation 0x3022b7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x30229ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x30194c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x30194a06 CFRunLoopRunInMode + 102
6 WebCore 0x38302266 RunWebThread(void*) + 414
7 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
8 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
9 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 3:
0 libsystem_kernel.dylib 0x3aedea8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3aede888 mach_msg + 44
2 CoreFoundation 0x3022b7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x30229ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x30194c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x30194a06 CFRunLoopRunInMode + 102
6 libAVFAudio.dylib 0x2f217584 GenericRunLoopThread::Entry(void*) + 124
7 libAVFAudio.dylib 0x2f20b99c CAPThread::Entry(CAPThread*) + 176
8 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
9 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
10 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 4 name: JavaScriptCore::BlockFree
Thread 4:
0 libsystem_kernel.dylib 0x3aef0f38 __psynch_cvwait + 24
1 libsystem_pthread.dylib 0x3af59224 _pthread_cond_wait + 536
2 libsystem_pthread.dylib 0x3af5a000 pthread_cond_wait + 36
3 JavaScriptCore 0x311b9d50 JSC::BlockAllocator::blockFreeingThreadMain() + 204
4 JavaScriptCore 0x311b73a0 WTF::wtfThreadEntryPoint(void*) + 12
5 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
6 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
7 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 5 name: JavaScriptCore::Marking
Thread 5:
0 libsystem_kernel.dylib 0x3aef0f38 __psynch_cvwait + 24
1 libsystem_pthread.dylib 0x3af59224 _pthread_cond_wait + 536
2 libsystem_pthread.dylib 0x3af5a000 pthread_cond_wait + 36
3 JavaScriptCore 0x31355236 JSC::GCThread::waitForNextPhase() + 74
4 JavaScriptCore 0x31355290 JSC::GCThread::gcThreadMain() + 48
5 JavaScriptCore 0x311b73a0 WTF::wtfThreadEntryPoint(void*) + 12
6 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
7 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
8 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 6 name: WebCore: CFNetwork Loader
Thread 6:
0 libsystem_kernel.dylib 0x3aedea8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3aede888 mach_msg + 44
2 CoreFoundation 0x3022b7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x30229ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x30194c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x30194a06 CFRunLoopRunInMode + 102
6 WebCore 0x3834ad5a WebCore::runLoaderThread(void*) + 250
7 JavaScriptCore 0x311b73a0 WTF::wtfThreadEntryPoint(void*) + 12
8 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
9 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
10 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 7 name: com.apple.NSURLConnectionLoader
Thread 7:
0 libsystem_kernel.dylib 0x3aedea8c mach_msg_trap + 20
1 libsystem_kernel.dylib 0x3aede888 mach_msg + 44
2 CoreFoundation 0x3022b7be __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x30229ee4 __CFRunLoopRun + 780
4 CoreFoundation 0x30194c22 CFRunLoopRunSpecific + 518
5 CoreFoundation 0x30194a06 CFRunLoopRunInMode + 102
6 Foundation 0x30bcf2f2 +[NSURLConnection(Loader) _resourceLoadLoop:] + 314
7 Foundation 0x30c44c82 __NSThread__main__ + 1058
8 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
9 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
10 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 8 name: WebCore: LocalStorage
Thread 8:
0 libsystem_kernel.dylib 0x3aef0f38 __psynch_cvwait + 24
1 libsystem_pthread.dylib 0x3af59224 _pthread_cond_wait + 536
2 libsystem_pthread.dylib 0x3af5a000 pthread_cond_wait + 36
3 JavaScriptCore 0x311b9e82 WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 58
4 WebCore 0x384353a8 WTF::PassOwnPtr<WTF::Function<void ()> > WTF::MessageQueue<WTF::Function<void ()> >::waitForMessageFilteredWithTimeout<bool (WTF::Function<void ()>*)>(WTF::MessageQueueWaitResult&, bool (&)(WTF::Function<void ()>*), double) + 104
5 WebCore 0x3843532e WebCore::StorageThread::threadEntryPoint() + 162
6 JavaScriptCore 0x311b73a0 WTF::wtfThreadEntryPoint(void*) + 12
7 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
8 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
9 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 9 name: com.apple.CFSocket.private
Thread 9:
0 libsystem_kernel.dylib 0x3aef1440 __select + 20
1 CoreFoundation 0x3022f680 __CFSocketManager + 480
2 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
3 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
4 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 10:
0 BLSOffline 0x000f7268 0x6c000 + 569960
1 BLSOffline 0x000f97f2 0x6c000 + 579570
2 BLSOffline 0x000f9c36 0x6c000 + 580662
3 BLSOffline 0x000e0142 0x6c000 + 475458
4 BLSOffline 0x000c39ce 0x6c000 + 358862
5 BLSOffline 0x000ce832 0x6c000 + 403506
6 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
7 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
8 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 11:
0 libsystem_kernel.dylib 0x3aef1c7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x3af57dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x3af57c80 start_wqthread + 4
Thread 12:
0 libsystem_kernel.dylib 0x3aef1c7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x3af57dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x3af57c80 start_wqthread + 4
Thread 13:
0 libsystem_kernel.dylib 0x3aef1c7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x3af57dc6 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x3af57c80 start_wqthread + 4
Thread 14:
0 libsystem_kernel.dylib 0x3aef1440 __select + 20
1 BLSOffline 0x0010346c 0x6c000 + 619628
2 BLSOffline 0x000fa5a2 0x6c000 + 583074
3 BLSOffline 0x000e00f2 0x6c000 + 475378
4 BLSOffline 0x000c4516 0x6c000 + 361750
5 BLSOffline 0x000c3682 0x6c000 + 358018
6 BLSOffline 0x000ce832 0x6c000 + 403506
7 libsystem_pthread.dylib 0x3af59c1a _pthread_body + 138
8 libsystem_pthread.dylib 0x3af59b8a _pthread_start + 98
9 libsystem_pthread.dylib 0x3af57c8c thread_start + 4
Thread 0 crashed with ARM Thread State (32-bit):
r0: 0x00000000 r1: 0x00000000 r2: 0x00000000 r3: 0x3ae94ab1
r4: 0x00000006 r5: 0x3cd8b18c r6: 0x00000c9b r7: 0x27d95390
r8: 0x00aed8d9 r9: 0x27d952e0 r10: 0x17783780 r11: 0x000000a8
ip: 0x00000148 sp: 0x27d95384 lr: 0x3af5aa33 pc: 0x3aef11fc
cpsr: 0x00000010
我们将设备保留太久以至于无法进入空闲模式，因此iPad屏幕会熄灭。然后我们唤醒了iPad，然后又开始使用那里的相同应用程序。
几秒钟后，应用程序崩溃了给定的日志。它似乎是因为UITableViewCell的创建而引起的。
以下是代码，我们如何在 cellForRowAtIndexPath 中加载单元格
static NSString* FlatCellIdentifier = @"DownloadCell";
CustomizeDownloadTableViewCell *cell = (CustomizeDownloadTableViewCell*)[tableView dequeueReusableCellWithIdentifier:FlatCellIdentifier forIndexPath:indexPath];
任何人都可以帮忙吗？可能是什么原因？