You can manually select the script by hitting the browse button next to the script field and select the script. In this case you probably want PlayMakerFSM. All the data is still there, it just needs to know what script to apply it to.
Did you move folders in finder/explorer? That's generally a bad idea. It's better to reorganize projects inside unity, so it can properly manage references. Even then I would always backup or use version control before making any project changes in unity!
