Hi OOPer, I've managed to resolve this issue by using sender.hidden = true Thank you for your explanation as to why I was receiving the error. My apologies for using the incorrect tag.

Yes, I did it in IBAction. My apologies, I have closed my old threads now.

Thread closed.

Perfect - thank you both, I'm still learning the basics of Swift so this information has been very helpful to know! 

Are there any functions which can be used to refresh it instead? Essentially all of the labels on my View Controller are assigned a database value, and when one of them are updated I need the View Controller to automatically update to reflect this new order of values.

Thanks all for your inputs, in the end I managed to get it working by creating a segue and programatically calling this using the following code: performSegue(withIdentifier: "showDetail", sender: nil)

Hi, thanks for your reply. For some reason, when I click the button nothing happens, despite re-adding the segue and adding the print("firstURL", firstURL) line - and nothing is shown. :( Any idea what it could be? Really baffling me, I even replaced the function above with a UIAlert and it didn't show either.