I get the same. It prolly has to do with that the sprite library/cache got bigger with the newly added nations in patch 3.10. In this case there's an easy fix: Remove the units from nations which have already been defeated. Stay tuned...
But even after deleting all sprites from New Ulm:
Code:
***** Error sprnbr 574, max 271, file 23
That's a very grave reduction in sprite numbers...
