Freeze during battle

The game freezes each time I go into battle. I am on a iMac using steam, version 2.0f9. Tried reinstalling the game, restarting the computer, verifying integrity of game files, changing to a lower video resolution, unchecking ambient obscurance, unchecking antialiasing, and setting texture resolution to low. Freezes during battle. Sometimes it will unfreeze and then freeze again.