Crash opening Pool window

So, I did a back up of a session to a separate folder.

But then went back to the previous version, project is playing back fine but as soon as I opened up the pool, all the listed audio files (again, session was playing fine) are red and a crash error occurs. Recreated twice. When it crashes, it creates a buzzing noise.
Screenshot 2016-10-18 21.19.11.png
Screenshot 2016-10-18 21.19.23.png