Well after a few irrecoverable GB campaigns because of CTD, there are a few things that has crashed my campaign everytime:

1. Hurons. Whether they declare war on you, or you on them, or you conquering their last regional capital, one of these will eventually happen and crash your game (as GB, since Hurons always declare war on GB). Bypassed this by not taking their last region.

2. Navy bugs. Lots of them. CTD can happen when you click on a military port (all other ports don't seem to crash your game), whether or not it has ships in it, troops, or nothing at all. clicking on your fleets also crashes your game. Apparently this happens randomly, so everytime I click on a fleet, its like playing Russian roulette, you never know if thats the next one that will crash your game. The bugged fleets cannot become "unbugged". It will stay bugged for the rest of the campaign, so it is essentially lost, but you still pay upkeep. I have at least 3 fleets of 10-12 ships of the line that is like this, thank god money is not an issue for GB.

3. Merging units. I usually never do this myself, but other people were saying it crashes the game so I tried it once and it did. Never tried it again.

Other than those, the game experiences jst random crashes every couple turns or so. It doesn't happen much, and you can usually continue from your last savepoint past where it crashed, but its sorta affected how I play the game, since I'm afraid the game can crash at any moment, I play a lot more cautiously than I normally do, and I tend to avoid clicking on ships as much as possible (which, playing as GB, is TOTALLY wrong)