This is the topic posted before. But I had a different situation. After I insert the IBOutlet line in “MainWindowController.swift”, I didn’t get a textField outlet in File’s Owner and an ! sign shows up in the window outlet. It says “MainWindowController does not have an outlet named window.”
According to the previous post, I checked the class name and found no error. I don’t know how to tackle this. Any help would be appreciated!