UIWebview respondsToSelector: message sent to deallocated instance

Question

I have a custom UITableviewCell with UIWebview which shows the error message

respondsToSelector: message sent to deallocated instance

while poping a new viewController.

Here is my code:

UITableViewCell *cell = [self.exhibitorDetailTbleVw cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:i]];
    if ([cell isKindOfClass:[SpeakerDescriptionTableCell class]]) {
         SpeakerDescriptionTableCell *cellTable = [self.exhibitorDetailTbleVw cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:i]];
         [cellTable.descriptionWebView setDelegate:nil]; 
         cellTable.descriptionWebView = nil; 
         [cellTable.descriptionWebView stopLoading];
     }

Still showing the error, any idea where i am doing wrong.