A gm posted this on a similar problem:
Clearing your Battle.net Cache
1. Navigate to Mac HD/Users/Shared/Blizzard/
2. Move the Battle.net folder to the trash.
3. Empty the Trash.
Repairing StarCraft II
1. Navigate to /Applications/StarCraft II/Battle.net
2. Delete the Battle.net.MPQ file
3. Launch StarCraft II
This will force the game to see it is missing data and self repair.
http://us.battle.net/sc2/en/forum/topic/6412104865