Question: I have a problem with a popover. If I tap on a cell I will load a popover to select more details. Everything works fine, but when I press my cell again I receive every time the following message:

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

If I tap on another cell I will not get this Warning. Only if a tap the same row again.

I tried lots of things but I am not able to solve this problem. I load my popover with like this:

```
var popover: UIPopoverController!
var popoverContent: ModalTableViewController!

```

and on my cell tap:

```
popoverContent = self.storyboard.instantiateViewControllerWithIdentifier("ModalTableViewController") as ModalTableViewController

popoverContent.selectedQuestionID = indexPath!.row               
popover = UIPopoverController(contentViewController: popoverContent)
popover.delegate = self

popover.presentPopoverFromRect(currentCell.LabelCellTitle.frame, inView: currentCell.LabelCellTitle.superview, permittedArrowDirections: UIPopoverArrowDirection.Left, animated: true)

```

And to dismiss

```
func popoverControllerDidDismissPopover(popoverController: UIPopoverController!) {

    popover.dismissPopoverAnimated(false) // just to check

    self.popover = nil
    self.popoverContent = nil

}

```

Any ideas?

Edit:

If I check with:

```
if(self.popoverContent == nil) {

```

before opening it, I'll find out that it's not nil when I tap the same cell again. 

Edit again:

I have the same problem if I create it with a little different setup:

Custom 1x1px Button. Connect popover with segue. On cell tap move button to cell and open popover.

So there is no code for opening the popover, only with storyboard editor.

I get the same error message (sometimes) just if I tap the same popover again.

Answer: 
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!
This happens if a UIActionSheet is presented at the moment of new view controller presentation call, for example
This code works for me

```
    [[NSOperationQueue mainQueue] addOperationWithBlock:^{
        [controller presentViewController:modalViewController animated:YES completion:NULL];
    }];

```