Can't open websites
Suddenly can't open any website pages, including the Firefox download url. Get "Secure Connection Failed" alert, PR_END_OF_FILE_ERROR , for everything.
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 There can be two possibilities: one is that the server is outdated and doesn't support modern cipher suites, another might be that the server only supports a few cipher suites and Firefox doesn't support any of these.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