Hi,
Have you patched your game up to date (1.63)?
Have you only recently installed Supernatural and did you have problems before you installed it? Did the installation seem to work? Perhaps you have a corrupted download.
Do you have any mods or custom content (if so, remove them until your game is working again).
For general advice, information and tips on how to play TS3 on a Mac, read BluebellFlora's guide here:
http://answers.ea.com/t5/The-Sims-3/Links-to-Mac-help-threads-and-guides/m-p/749664#U749664
In particular, try moving out the whole TS3 folder from Documents and onto your desktop, let the game generate a new one and then see if you can play. It is possible that there is some problem within your current setup.
Caspin
