@Camo_Girl2011 Could you please try the following:
Let us know how you get on!
@Nycarious Just to double check, did you try the steps in posted just above?
If you did, what exact error do you receive and are you able to log in in-game?
I had this exact same problem after doing a restore on Windows 10. Literally all I did to fix it was type in IE in the windows search bar to find internet explorer. Then went to tools - internet options - advanced tab - and reset. Fixed the issue no problem. OI have no idea why Sims 3 Launcher uses Internet Explorer. Seeing as how I don't even use Edge or Internet explorer. But this was really annoying.
In case this still doesn't work for anyone, my problem was because IE was not my default browser. Change your default browser to IE and see if that works.
Same here. Damn log in window just keeps popping up again and again and again and again! Still refuses to download the hairstyle that i bought. plus, the welcome tab of the launcher is still blank. This didn't start until i bought something new after the last update!
Same. I've done everything that has been suggested. I can log in everywhere except for the dang launcher. I hope it starts working soon, I wanna download the boardwalk.