problem playing the sims 2

I'm trying to play the sims 2 on my mac osx and it keeps saying i need to free up some space on my disk.. how do i do that? and i've played it on this computer before a while back but for some reason it wont let me now. help would be greatly appreciated. thanks

it says i have 206.97 GB left but the message on the sims says i need 1 MB... i'm pretty sure i have enough.