Hi! I have a calculator app on the App Store and I was thinking of publishing on the Mac App Store as well. When running the app on the Mac via Catalyst everything in the app works fine aside from a basic function. When clicking the number buttons, the UILabel which is the calculator's "display" does not change and shows the default "0" value. This is the part of the code: @IBAction func numberBtn(_ sender: UIButton) {         if runningNumber.count <= maxLength {             if OutletLbl.text != "0" {                 runningNumber += "\(sender.tag)"                 OutletLbl.text = runningNumber                 lastNumber = "\(sender.tag)"             } else {                 runningNumber = "\(sender.tag)"                 OutletLbl.text = runningNumber                 lastNumber = "\(sender.tag)"             }         } } Legend: maxLength = the max number of digits the display of the user's device can fit runningNumber = the variable which stores the current number which is then displayed in the OutletLbl OutletLbl = the calculator's display label with the problem in question sender.tag = the value of the number button pressed lastNumber = variable which stores the value of the last number button pressed for continuous operations Any ideas? Thanks in advance