'Build input file cannot be found' Swift 4.2, Xcode 10.0

Question

I am getting the following error when building in Xcode 10.0 with swift 4.2:

Answer 1

This works if you get the 'Build input file cannot be found error message' and also have files that are red in the inspector:

1. Open your project folder in Finder

2. Make a copy of the affected files onto your Desktop

3. Delete the affected files in Xcode and then close Xcode

4. Re-Open Xcode and drag your copied files into your Xcode project

This worked for me. Before I got the error message I was re-organising files in the file inspector which gave me that error message and made the files I was moving around turn red. Hope this helps !!