SIGABRT

2016-04-02 11:00:54.271 Times Table[1363:23482] *** Assertion failure in -[UITableView _configureCellForDisplay:forIndexPath:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3512.60.7/UITableView.m:7971
2016-04-02 11:00:54.274 Times Table[1363:23482] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView (<UITableView: 0x7a160200; frame = (-4 58; 328 510); clipsToBounds = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7b457670>; layer = <CALayer: 0x79e675d0>; contentOffset: {0, 0}; contentSize: {328, 2200}>) failed to obtain a cell from its dataSource (<Times_Table.ViewController: 0x79f655a0>)'
*** First throw call stack:
(
	0   CoreFoundation                      0x0021d494 __exceptionPreprocess + 180
	1   libobjc.A.dylib                     0x01f31e02 objc_exception_throw + 50
	2   CoreFoundation                      0x0021d32a +[NSException raise:format:arguments:] + 138
	3   Foundation                          0x00662322 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 118
	4   UIKit                               0x00b8a868 -[UITableView _configureCellForDisplay:forIndexPath:] + 228
	5   UIKit                               0x00b9796b -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 877
	6   UIKit                               0x00b97a7d -[UITableView _createPreparedCellForGlobalRow:willDisplay:] + 90
	7   UIKit                               0x00b67b32 -[UITableView _updateVisibleCellsNow:isRecursive:] + 3347
	8   UIKit                               0x00b86416 __29-[UITableView layoutSubviews]_block_invoke + 52
	9   UIKit                               0x00ba16cc -[UITableView _performWithCachedTraitCollection:] + 88
	10  UIKit                               0x00b862eb -[UITableView layoutSubviews] + 214
	11  UIKit                               0x00adc3d4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 810
	12  libobjc.A.dylib                     0x01f46059 -[NSObject performSelector:withObject:] + 70
	13  QuartzCore                          0x05321096 -[CALayer layoutSublayers] + 144
	14  QuartzCore                          0x053148b6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 388
	15  QuartzCore                          0x0531471a _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
	16  QuartzCore                          0x05306ee7 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 317
	17  QuartzCore                          0x0533b847 _ZN2CA11Transaction6commitEv + 561
	18  QuartzCore                          0x0533c108 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92
	19  CoreFoundation                      0x0012f75e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
	20  CoreFoundation                      0x0012f6be __CFRunLoopDoObservers + 398
	21  CoreFoundation                      0x00124868 CFRunLoopRunSpecific + 504
	22  CoreFoundation                      0x0012465b CFRunLoopRunInMode + 123
	23  UIKit                               0x00a062da -[UIApplication _run] + 540
	24  UIKit                               0x00a0beb9 UIApplicationMain + 160
	25  Times Table                         0x00030631 main + 145
	26  libdyld.dylib                       0x02948a25 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)