Hello, chvbob, and thanks for contacting Mozilla Support.

You may try to disable IPv6.

To disable IPv6, change the preference network.dns.disableIPv6 from "false" to true . Here are the steps:

1. Type about:config in the address bar, press Enter. 2. Find network.dns.disableIPv6 in the list. 3. Right-click -> Toggle. 4. Restart your Mozilla application and try again.

If this doesn't work, you can re-enable IPv6 by resetting the preference to "false" (double-click to toggle).

Here's an interesting article about another problems, including IPv6, that may help you if the first advice didn't work.

Please, make sure you check everything in the article and contact us again if none of the solutions worked.

This is FJM8 from Mozilla Support, thank you for contacting us and have a nice day!

It is possible that your security software (firewall, anti-virus) blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access to install for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

• https://support.mozilla.org/kb/fix-problems-connecting-websites-after-updating