Whenever I try to play the game on my new OS, it plays alright for a few turns, then crashes. Has this issue been addressed before? Is there anything I can do to fix it?
Sounds like it could be a corrupt "key.file". If you still have your manual handy, look in your Dominions3 folder for the file named "key.file", back it up, delete it, then start Dominions, and re-enter the CD-key from your manual.