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.

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)

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.

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

Thread closed.

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

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.