Web search: https://www.bing.com/search?q=pr_end_of_file_error

radi.stoyanov said Turns out the option DNS over HTTPS is what caused the problem.

jamesafuf123 said https://support.mozilla.org/en-US/questions/1264659#answer-1237475 my ISP was blocking sites like that

cor-el said This usually means that Firefox wasn't able to find a cipher suites to use to connect to this server and reached the end of the list. There can be two possibilities: one is that the server is outdated and doesn't support modern cipher suites, another might be that the server only supports a few cipher suites and Firefox doesn't support any of these.

You can check your browser and possibly compare this with the server setup.

• https://www.ssllabs.com/ssltest/viewMyClient.html

This could be a problem with your Avast security software or with one of the extensions (Avast AntiTrack Premium) it has added to Firefox.

You also have a weird user agent that have some random string added to it.

• Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0/YIRbvYPD-6

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems