Caw FAQ's........Links to Tutorials, and Resources. Textures, & Troubleshooting

Looks like MTS is up again. I pulled some info for you though.

This is from Simsamples troubleshooting thread Here

CAW opening screen flashes, but CAW will not run:
JadedSidhe advises a solution to this problem in THIS post. Running the CAW executable as an administrator will bypass any UAC restrictions which cause this problem.
Another way of preventing this issue would be to install your CAW tool and the Sims 3 game to a non-default location, for example C:\ Games. This would ensure that UAC does not affect the running of your game.

I had this happen once, and clearing the Virtual Store Files worked for me, info HERE.

Let me know if something here works.