Move Xcode Project Causes Red Text (Missing Files from Project)

Files in Xcode not working (names in red)

If files marked in red, they are "not found" by Xcode.

You either moved or deleted them within File Finder, outside Xcode.
Delete the red marked files within XCode, then add them again to XCode.

This will solve your problem.

Xcode 9 - Some folders marked with red text

Check this.

It means they are not found on disk where your project believes they should be. Control-click and Show In Finder to see the folder location to locate the file and drag it back in to the project, and delete the bad reference.Missing. Maybe you moved them somewhere without deleting them from the project or something.

Edit: Don't delete it before add it first, and you should save backup from the files in another folder, also you have to use source controls like Bitbucket, GitHub, or GitLab.

Dragged files into Xcode show up as red, automatically using wrong path

Delete the group files AND group folder, not just the group files! The group folder has its own path that is causing group files under it to have an incorrect path.

Does anyone know why if I move a xcode project to another computer some files are broken?

Get Info on the files in question in the Groups & Files list, and ensure that Path Type is set to one of the relative values. Mostly likely the files that are showing as missing were set to Absolute.

Frameworks are 'red' in Xcode

The red text indicates that the actual files are not at the path that the project has for them.

Get info on the framework and look under the General tab. The first section shows the name and path of the framework bundle itself. The most common cause of a problem with system supplied frameworks is that the path type has been changed to something that breaks the path. The default setting is Relative to Current SDK. Change the path until you get one that leads to the actual framework.

If you have the developer tools installed in a custom location, you are more likely to run into this problem. If you copy a project from someone with non-standard settings, you can encounter it as well.