We can’t connect to the server
Hmm. We’re having trouble finding that site.
We can’t connect to the server at www.google.com.
If that address is correct, here are three other things you can try:
Try again later. Check your network connection. If you are connected but behind a firewall, check that Firefox has permission to access the Web.
OTHER BROWSERS ARE WORKING
Alla svar (3)
Sorry to hear about this problem. Are you able to open any sites, such as mozilla.org or wikipedia.org ?
There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connection certificates and send their own.
https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites
https://support.mozilla.org/en-US/kb/secure-connection-failed-firefox-did-not-connect
https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors
It is an on-again / off-again problem. Either Firefox works or I can't access any website. I reinstalled Firefox and tried the solutions suggested in the links you provided.
Thanks for your response.