PC Ableton Live users: has Backbone wrecked your Undos/Crash Reports?

I bought Backbone, and was running it in a clean project: tweaking sounds, having fun. It’s a great instrument.

However, there was a problem on shutting down Live when I was done. I got a few error messages, the last of which is completely new to me. It announced that my Undos and Recovery would no longer work:

“Failed to access Undo history file. Switching to memory-based undo. Live will not be able to recover Sets after crashes anymore.”

I get this same message every time I load Live now, during the VST scan. I want to send a Crash Report to Ableton’s Support, but I can’t because whatever has gone wrong has wrecked this too: no Crash zips are being saved. I’m also seeing some odd hitches when sweeping Backbone’s pots now, which is suggestive of that Undo issue — as though whatever new Undo buffer it’s created in memory is filling up and hanging for a second while it clears space. This shouldn’t be a problem (I have 32GB RAM), but having never encountered this alternative Undo arrangement I have no idea if this space is a fixed size regardless of capacity.