Re: The Sims 3 Launcher keeps asking me to log in
@aodoherty Does the same thing happen in a clean Sims 3 folder? Actually, before you go that route, delete the file with your email address in the name in Documents\Electronic Arts\The Sims 3\Downloads, and see whether that helps. If it doesn't, try the clean user folder.
Please also clear both the cache for Internet Explorer and the one for whichever browser you're using to download store content. The launcher uses IE, and your browser will be involved too.
If these steps don't help, try changing your password to something with only letters and numbers, no special characters, accents, or really anything you wouldn't find in English. The launcher periodically stops working properly with certain symbols, for no apparent reason, and that can also sometimes cause exactly this problem. No idea why.