It’s almost certainly a discrepancy between the value returned from the UITableViewDataSource method:
tableView:numberOfRowsInSection:
and the call to:
tableView:cellForRowAtIndexPath:
Where tableView:numberOfRowsInSection: is returning more rows than tableView:cellForRowAtIndexPath: can provide.
However you don’t provide enough information to help further.
solved My Application Crashes While Reloading table data [closed]