I don't know if it's the same issue I ran into, but this is what happened to me when I was messing around with modifying armor stats in game.
I added the following boost to a piece of gear and I had the same issue pop up, crashing at dice rolls.
"MinimumRollResult(RawAbility,20)"
Turns out there's an issue with the game calculations for tool tips that causes this particular crash.
Here's where I learned about it from Norbyte