I've been having the same error ever since switching to 1.14 from 1.13. The error doesn't always trigger, it was like 50% chance of triggering so i would just open up the campaign file again. But lately it's been more like 95%. Even if i delete my lib token and save it that way, the error continues this time not even showing error and opening a blank maptool file instead of the campaign file.

Another thing i found is that the "95% chance of erroring" is retroactive meaning that i save my campaign files regularly while working on my framework and the older versions of my campaign files have the same chance of error. So it isn't a very broken macro triggering, i use oncampaignload for defining functions and i tried to delete all my defined functions and save it that way. Didn't solve the problem.

I think you're going to have to share the problem campaign file. If this was a common issue we'd be seeing a lot more reports.

I believe this is the same underlying issues as #4542.