@IBOutlet and @IBAction refers to wrong project, how to get rid of those references?

Question

I have copied and pasted some source code from one old xcode-project to another new project.

Included in the copied code where some @IB

Answer 1

I have same problem. To solve this problem you should (for macOS Catalina 10.15.4, Xcode Version 11.1):

1. Close your project and close Xcode
2. Open /Users/XXXXX/Library/Developer/Xcode/DerivedData and delete your cache of project
3. Open /Users/ХХХХХ /Library/Developer/Xcode/DerivedData/ModuleCache.noindex and delete all cache from this directory
4. Open your project again and click Product > Build