Okay, this is a bit of a weird one so I'll start a couple of days back.
I bought Island Paradise and installed it, then spent the evening playing around. The next day on trying to load the game I kept getting an unknown error. Looking around the internet for resolving this on a Mac (OSX 10.7 I think) I found the suggestion to go into [user]/Library/Preferences/The Sims 3 Preferences and delete system.reg, as well as any transgaming files in the Preferences folder. I did that and the game started working again, except that it was acting like I'd never played before - popping up tutorials, not showing save files, etc. That wasn't really a problem for me and I started a new game and carried on.
Now, my save files and mods and things actually still exist. The Electronic Arts folder in Documents is still there, but the game isn't recognising it. I then renamed it to see if the game would generate a new one, which it hasn't. So while I can still play normally with my new save file and everything there is fine, I can't put the mod files back into the game to get custom content, and more importantly I can't find the actual save file for the game I'm playing. This is an issue because I was doing a back up/erase/restore of my computer (it's a few years old and had been running slow) and in the process discovered that Sims runs a LOT better when I boot from the external drive I backed my computer up onto than from my actual computer.
Part of this I suspect is space - it's a 2TB external drive, and the back up is on a 1TB partition, whereas my computer has a 500GB hard drive, and my files take up 440GB altogether. So there's only 60GB of space free on the Mac, but over 500GB free on the external. I'll probably move all my video files onto the other partition of the external drive later to free up space, but what I actually wanted to do was move the more recent save file from my Mac to my external drive so I can play while booting off that without losing the progress I made today while I was discovering that it's still annoyingly slow. But I can't, because I can't find the save file. There's now no Electronic Arts folder in Documents, because I renamed the old one, and the old one still has all my old saves but not the new one. I ran a search on what the file name should be and nothing came up. If I open the game, it shows the family fine and I can load it and keep playing, but I have no idea where it's storing the information.
Sooo... anyone have any idea? Where is it drawing the data from, if not the Electronic Arts folder?
