CP_0
Does it crash during a turn in the Campaign? If so, open the map and see what it's doing. It might be interacting with an object, and the crash occurs after that interaction, which might not have happened before because you were ignoring that object.
I opened it, looked, and the AI doesn't even have time to do anything (it crashes after my turn ends, sometimes on turn 10 or 13), and before the crash, everything is standard. No errors were displayed in the console either.
Added 8 minutes later
I'm already thinking of just deleting the game and installing a couple of helpful/cosmetic mods. Is there a list of the modifications included in EWA that has been published anywhere? (Some of them are really good). I remember having a perfect build on my disk once, with all the Campaigns combined into Heroes of Might & Magic V: Tribes of the East, additional music (Lilium from Elfen Lied, etc.), and possibly some minor graphical changes, but it definitely wasn't Epic War Age.
UPD
Miracles... I reinstalled the mod, and now the Campaign isn't crashing, lol.