Heard back and they said to try adding a blank step (like a blank Filter step) to the pipeline right after Import and checking it in to see if that does the trick. The assumption is that the error occurs randomly in projects that were converted from R11 - it's looking for legacy config that no longer exists (not sure why it does that, though). "Old habits die hard" isn't just for humans, I suppose. ;-)
#TBMStudio