This sounds more like a complaint than an actual request for help but if you are willing to give things a try, I suggest this:

1. Download the Aurora version of Firefox from http://www.mozilla.org/firefox/aurora/
2. Type about:support into the address bar. This will open the Troubleshooting Information page.
3. Click the Reset Aurora button in the upper-right corner. This will reset everything to it's default state while saving bookmarks and passwords; hopefully fixing whatever is causing the problems you are seeing.

After doing this, you don't have to continue using Aurora (pre-release version of Firefox), you can switch back to regular Firefox if you want (or Chrome obviously).

Which security software (firewall, anti-virus) do you have?

A possible cause is security software (firewall) that 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