I had a rule crash and become unrecoverable when I was moving an action. I was created a new action (simple conditional action) and it was at the bottom of my list. I used the cut function to move the action. When I clicked the paste icon on one of the other actions further up on the list, I got an "unexpected error". I can no longer edit the rule because any time I go into actions I receive the same error. See screenshots.
I'm on the latest build.