Unable to get map from server on Mac

[jamz]

This is almost always because you don't have permission to get the map, either because you can't write to the maps folder, or, as it seems in this case, AC can't change the name of your existing map (it wants to rename it to ac_edifice_xxxxxxxxxx.bak). RR's advice to delete your current version of the map should cure this, but if it happens with other maps, you'll have to investigate the underlying problem.