Hi,
Global variables were stored on a GameObject in an early beta for 1.2.
Over the course of the beta, we decided it made more sense for globals to be an asset that could be accessed from any scene, so we moved them to PlayMakerGlobals.asset for the final 1.2 release.
Unfortunately there is no way to automatically migrate globals from a GameObject component - officially that functionality was never released! Sorry! That's the downside of early access to features in the beta - sometimes they change before release
You can try adding the globals again, and see if the saved FSMs pick up the new globals. There's a good chance they will, but I can't say for sure, not knowing the beta version you were using... if they don't update automatically, you'll need to go through and hook up the new globals manually.