Problems after upgrading to Xcode 10: Build input file cannot be found

For me In Xcode 10, this solution worked like a charm. Just go to the Recovered References folder and remove all files in red color and add it again with proper reference. If Recovered References folder was not found: Check for all missing files in the project (files in red colour) and try to add files references again.

For Swift files or files that belong to the project such as:

Build input file cannot be found: PATH/TO/FILE/FILE.swift

This issue can happen when files or folders have been removed or moved in the project.

To fix it:

1. Go in the project-navigator, select your project

2. Select Build Phasestab

3. In Compile Sources section, check for the file(s) that Xcode is complaining of

4. Notice that the file(s) have the wrong path, and delete them by clicking on the minus icon

5. Re-add the file(s) by clicking the plus icon and search in the project.

6. Product > Clean Build Folder

7. Build

You generally find these missing files in the Recovered References folder of Xcode in the project tree (look for the search bar at the bottom-left of Xcode and search for your complaining file):

Deleting them from this folder can also solve the error.

Try to switch back to the Legacy Build System (File > Project Settings > Workspace Settings > Legacy Build System)

Just check the path to .plist file in Build Settings of your target