Hi Blaise,

That's weird. Please try the steps below and see if the problem persists. If it does, it may indeed by either a Firefox issue or an issue with the website blocking Firefox. But let's exclude the simplest causes first!

1. Please check if you have Enhanced Tracking Protection (ETP) enabled. You can do that by clicking the shield icon at the left of the address bar.
   • If ETP is enabled, try disabling it.
2. If the problem is not fixed, try clearing Firefox cache.
3. If it does not help, also try clearing cookies and data for the website you experience troubles with (warning: you will be logged out on this website).
4. If it also does not help, try running Firefox in Troubleshoot Mode.

How did it go? Looking forward to your update!

Disabling ETP did not help. Clearing Firefox cache did not help. Firefox will not let me connect to the SSA's website, so I can't clear those cookies and data. I refuse to go down the Troubleshoot Mode rabbit hole.

I have seen that I am not the only user experiencing this problem. The fact that I can reach the SSA when I switch to Chrome tells me that Firefox has a problem. Please own it and resolve it if maintaining a high regard for your service matters to you.

The people who answer questions here, for the most part, are other users volunteering their time (like me), not Mozilla employees or developers. If you want to inform the developers about an issue, you can also file a bug report or feature request. See File a bug report or feature request for Mozilla products for details.

Also, to make it clear: there's no way for anyone to triage your bug since we don't have a URL, and even if we did, an account would have been needed (that's how I understand your post, at least). Troubleshoot Mode temporarily disables add-ons and some features, and it may help if an extension causes the issue (and you use several of them, including uBlock). So I'd still recommend to try it.

I’m sorry I complained. Please forgive my cranky, seventy-three-year-old attitude.

Just to make it clear, the URL that Firefox cannot take me to is https://www.ssa.gov/myaccount/. That is the sign-in page, before an account number is needed. And the error message reads: Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.

The instructions for using Troubleshoot Mode look too long and complicated for me. For now, I will keep Chrome handy for those times when Firefox lets me down.

Please also forgive me if my answer sounded unfriendly, and thank you for the update. My Firefox loads this URL successfully, so the root of the issue should lay in your add-ons/settings.