Xcode error: "Failed to save .xcodeproj"

Question

I encountered an error message I have never seen before in Xcode. It is alerting me that it failed to save the project because it has been modified outside of Xcode. But as far as I know I did not modify it beyond the scope of Xcode.

I did recently perform a pod install to update some cocoa pods. That would be the only other modification to my project that I know of. That was some time ago before attempting to 'save', so I'm not sure it this is the problem.

QUESTION

How could my project be modified without my knowledge, and what would be the various results upon choosing to "Keep Xcode Version" or "Read From Disk"?

Answer 1

This message means that your files was modified not from Xcode(usually it happens if you changing something in Xcode and out Xcode in same time). It's similar to merge conflicts

If you has changed anything in project by calling pod install - it could lead to this error

Keep Xcode Version will resolve it by using Xcode changes which is stored in memory. Read From Disk will resolve it by using changes stored on disk