Firefox can't load websites but other browsers can is a good place to start

Thanks. I can't get on using other browsers either, but this seemed to happen as a result of an update to Firefox.

an update to Firefox won't break the internet for your whole computer. Do you have other computers on the same connection? Are they working?

I am using an iPad off the same connection so no problem with that. Also the network diagnostics doesn't detect any problem.

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 internet 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