My game launcher won't let me log in. The welcome page is initially blank, and then displays this message: "The website cannot display the page." I can't log in in-game either. I've tried to implement many of the 'fixes' for this issue (such as resetting Internet Explorer, clearing cache, verifying the game files on Steam - the works), but nothing seems to be working. Should I simply wait it out? Any advice would be much appreciated.

Are you still having this issue?

@PeculiarPlumbob any update?
I'm having this issue. I used to be able to fix it once upon a time by clearing the data from Internet Explorer (now Microsoft Edge), but it doesn't work. Everything was fine yesterday/earlier today, I could download without any issues. Then boom, I tried to download Monte Vista from my store account, and instead of it loading into the launcher, the login window pops up continuously and won't let me log in. However I can log in in-game just fine. But it does this with any of the purchased store cc I try to download to the launcher.

I tried everything recommended so far beside changing my password, b/c it has no special characters, but "the website cannot display the page" and login window spam is consistent for me. It's just crazy and aggravating because it happened literally out of nowhere.

If you have any kind of third-party antivirus software, it may block the inbound or the outbound internet access to the launcher. If you don't have one, you should check the firewall for the same reason.

If the antivirus program is not causing the issue, you should check for if your telemetry option is enabled (in Options file in Documents/Electronic Arts/TheSims 3...).
it must be enabletelemetry=1

Did you find the solution?