What security software do you have?

It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and other processes like the updater.

See:

• https://support.mozilla.org/en-US/kb/server-not-found-connection-problem
• https://support.mozilla.org/en-US/kb/Firewalls
• https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating

Does it still happen in Troubleshoot Mode?

Do you have an extension called FastPix installed?

Thanks so much for the interest. I have learned my problem only happens with my IPad and not being very savy I may have been on the wrong planet and wasted everybody's time for which I apologise. If anybody can point me in the right direction I would be grateful.