Is the game stuck? I set my settings to the lowest quality, that way it doesn't use up as much space, and the game works better. Maybe you could uninstall, than delete your safe file and than reinstall. Than the game will create a new safe file, and hopefully it won't happen again.
I'm no expert on this, by the way, so I'm just suggesting something you can try out. I don't know if it's going to work. For me the game crashes when I close it. And the only way to completely shut it is to turn of the computer. So I don't trust it. I think if that's going to happen often, it will destroy my laptop so I uninstalled the game.