I just encountered this same issue. Yikes.
Any word on a fix? I'm on Uv5.3.5, and PMv1.8.1.
Edit- I've reinstalled PlayMaker several times. Deleted anything generating errors. No change.
Edit- This might be related to removing unrelated (?) project folders. I deleted several folders from my project prior to this happening. PlayMaker recovered its actions when I restored the deleted files.
One of the deleted elements was Koreographer, which has some PlayMaker actions included with it, but none of these files or folders were part of the main PlayMaker directories.
I can verify that nothing from any of the PlayMaker folders or AddOns was touched, but maybe external tools modify something I'm not aware of. Would love to know more about this. PlayMaker never generated any errors during this issue.
Thanks in advance for the help!