Warning: Attempt to present ModalTableViewController on MainTableViewController which is already presenting (null)

I had this issue because I was trying to perform segue / present from within:

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex

I changed it to:

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex

and it fixed it!