It takes so long to save a sim game that hate doing it often, but I also hate losing 3 hours of gametime since my freetime is so limited by the demands of real life.
Therein lies your problem, most likely.
Error 12 is a world cache failure which, more often than not, is the result of the limitations of your machine. It's probably not something that EA has the ability to fix.
Some advice: first of all, you should be saving
far more often than every 3 hours. I save every 30 minutes, but realistically speaking you should save, at the
very least, every hour or so. Yes, it takes a long time to save, but not nearly as long as recovering 3 hours of lost play time. I speak from personal and very painful experience on this. If you're not opposed to mods, there's a very non-intrusive mod called "
Saver" which reminds you to save your game at specific intervals. You can set exactly how much time passes between prompts to save.
Also, since the world cache is rebuilt every time you start the game, you should exit completely out of it every couple of hours and restart it. I've also recently discovered that reducing the tree detail, even slightly, goes a long way to prevent this, too. If you continue to have trouble with it, you should try to reduce your graphics detail even more. Just because your settings are at default does not exactly mean that they're the best settings, and reducing the detail has absolutely no negative impact on playability.
