title: UITableView crash when selecting
body: <p>I have a simple table view controller driven by the fetchedResultsController and it crashes very often when I select it and the crash log is like this;</p>
  
  <pre><code>Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
  Exception Codes: KERN_INVALID_ADDRESS at 0xc21eb7ad
  Crashed Thread:  0
  
  Thread 0 name:  Dispatch queue: com.apple.main-thread
  Thread 0 Crashed:
  0   libobjc.A.dylib                 0x3c0ce5d0 objc_msgSend + 16
  1   UIKit                           0x3623c564 -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:withIndexPath:] + 404
  2   UIKit                           0x3622138c -[UITableView(_UITableViewPrivate) _updateVisibleCellsNow:] + 1312
  3   UIKit                           0x36238822 -[UITableView layoutSubviews] + 202
  4   UIKit                           0x361f48c2 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 254
  5   QuartzCore                      0x35fa050e -[CALayer layoutSublayers] + 210
  6   QuartzCore                      0x35fa00b0 CA::Layer::layout_if_needed(CA::Transaction*) + 456
  7   QuartzCore                      0x35fa0fd4 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 12
  8   QuartzCore                      0x35fa09be CA::Context::commit_transaction(CA::Transaction*) + 234
  9   QuartzCore                      0x35fa07d0 CA::Transaction::commit() + 312
  10  QuartzCore                      0x35fa0634 CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 56
  11  CoreFoundation                  0x343b793e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 18
  12  CoreFoundation                  0x343b5c34 __CFRunLoopDoObservers + 272
  13  CoreFoundation                  0x343b5f8e __CFRunLoopRun + 742
  14  CoreFoundation                  0x34329238 CFRunLoopRunSpecific + 352
  15  CoreFoundation                  0x343290c4 CFRunLoopRunInMode + 100
  16  GraphicsServices                0x37f07336 GSEventRunModal + 70
  17  UIKit                           0x362452b4 UIApplicationMain + 1116
  18  Introdex                        0x0011e538 0xa3000 + 505144
  19  Introdex                        0x000a5a24 0xa3000 + 10788
  
  Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
  Thread 1:
  0   libsystem_kernel.dylib          0x3c5b75d0 kevent64 + 24
  1   libdispatch.dylib               0x3c4f2d22 _dispatch_mgr_invoke + 806
  2   libdispatch.dylib               0x3c4ee374 _dispatch_mgr_thread + 32
  
  Thread 2 name:  WebThread
  Thread 2:
  0   libsystem_kernel.dylib          0x3c5b6e30 mach_msg_trap + 20
  1   libsystem_kernel.dylib          0x3c5b6fd0 mach_msg + 48
  2   CoreFoundation                  0x343b72b6 __CFRunLoopServiceMachPort + 126
  3   CoreFoundation                  0x343b602c __CFRunLoopRun + 900
  4   CoreFoundation                  0x34329238 CFRunLoopRunSpecific + 352
  5   CoreFoundation                  0x343290c4 CFRunLoopRunInMode + 100
  6   WebCore                         0x3a328390 RunWebThread(void*) + 440
  7   libsystem_c.dylib               0x3c5200de _pthread_start + 306
  8   libsystem_c.dylib               0x3c51ffa4 thread_start + 4
  
  Thread 3:
  0   libsystem_kernel.dylib          0x3c5b6e30 mach_msg_trap + 20
  1   libsystem_kernel.dylib          0x3c5b6fd0 mach_msg + 48
  2   CoreFoundation                  0x343b72b6 __CFRunLoopServiceMachPort + 126
  3   CoreFoundation                  0x343b602c __CFRunLoopRun + 900
  4   CoreFoundation                  0x34329238 CFRunLoopRunSpecific + 352
  5   CoreFoundation                  0x343290c4 CFRunLoopRunInMode + 100
  6   Foundation                      0x34c4d5be -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 250
  7   Foundation                      0x34cf0c40 -[NSRunLoop(NSRunLoop) run] + 76
  8   Introdex                        0x0021924c 0xa3000 + 1532492
  9   Foundation                      0x34cfa22c __NSThread__main__ + 968
  10  libsystem_c.dylib               0x3c5200de _pthread_start + 306
  11  libsystem_c.dylib               0x3c51ffa4 thread_start + 4
  
  Thread 4 name:  com.apple.NSURLConnectionLoader
  Thread 4:
  0   libsystem_kernel.dylib          0x3c5b6e30 mach_msg_trap + 20
  1   libsystem_kernel.dylib          0x3c5b6fd0 mach_msg + 48
  2   CoreFoundation                  0x343b72b6 __CFRunLoopServiceMachPort + 126
  3   CoreFoundation                  0x343b602c __CFRunLoopRun + 900
  4   CoreFoundation                  0x34329238 CFRunLoopRunSpecific + 352
  5   CoreFoundation                  0x343290c4 CFRunLoopRunInMode + 100
  6   Foundation                      0x34c76888 +[NSURLConnection(Loader) _resourceLoadLoop:] + 304
  7   Foundation                      0x34cfa22c __NSThread__main__ + 968
  8   libsystem_c.dylib               0x3c5200de _pthread_start + 306
  9   libsystem_c.dylib               0x3c51ffa4 thread_start + 4
  
  Thread 5 name:  com.apple.CFSocket.private
  Thread 5:
  0   libsystem_kernel.dylib          0x3c5c7594 __select + 20
  1   CoreFoundation                  0x343bb474 __CFSocketManager + 676
  2   libsystem_c.dylib               0x3c5200de _pthread_start + 306
  3   libsystem_c.dylib               0x3c51ffa4 thread_start + 4
  
  Thread 6 name:  JavaScriptCore::BlockFree
  Thread 6:
  0   libsystem_kernel.dylib          0x3c5c708c __psynch_cvwait + 24
  1   libsystem_c.dylib               0x3c518afc _pthread_cond_wait + 644
  2   libsystem_c.dylib               0x3c518870 pthread_cond_timedwait + 40
  3   JavaScriptCore                  0x382fddf6 WTF::ThreadCondition::timedWait(WTF::Mutex&amp;, double) + 102
  4   JavaScriptCore                  0x38410532 JSC::BlockAllocator::blockFreeingThreadMain() + 78
  5   JavaScriptCore                  0x38423030 WTF::wtfThreadEntryPoint(void*) + 12
  6   libsystem_c.dylib               0x3c5200de _pthread_start + 306
  7   libsystem_c.dylib               0x3c51ffa4 thread_start + 4
  
  Thread 7 name:  JavaScriptCore::Marking
  Thread 7:
  0   libsystem_kernel.dylib          0x3c5c708c __psynch_cvwait + 24
  1   libsystem_c.dylib               0x3c518afc _pthread_cond_wait + 644
  2   libsystem_c.dylib               0x3c522cf8 pthread_cond_wait + 36
  3   JavaScriptCore                  0x383a36dc JSC::SlotVisitor::drainFromShared(JSC::SlotVisitor::SharedDrainMode) + 140
  4   JavaScriptCore                  0x383a3620 JSC::MarkStackThreadSharedData::markingThreadMain() + 140
  5   JavaScriptCore                  0x38423030 WTF::wtfThreadEntryPoint(void*) + 12
  6   libsystem_c.dylib               0x3c5200de _pthread_start + 306
  7   libsystem_c.dylib     
  </code></pre>
  
  <p>Can somebody please explain me what this crash log means. I could not read it properly and do not know what this actually means. It would be really great if anyone could help me.</p>