*If you don't connect to the Internet through a proxy (or don't know whether you connect through a proxy), select No Proxy.
       *If you connect to the Internet through a proxy, compare Firefox's settings to another browser's (such as Internet Explorer — see Microsoft's guide to proxy settings). 

hello bill0287.......... '''follow the steps:''' '''Firefox connection settings''' * Click the ≡ menu button. and select Options. * In the General panel, go down to the Network Settings section. * In the Network Settings section, click Settings…. * Change your proxy settings: *If you don't connect to the Internet through a proxy (or don't know whether you connect through a proxy), select No Proxy. *If you connect to the Internet through a proxy, compare Firefox's settings to another browser's (such as Internet Explorer — see Microsoft's guide to proxy settings). * Close the Connection Settings dialog. * Close the about:preferences page. Any changes you've made will automatically be saved. ''If you find that changes you make to your Firefox connection settings are not remembered when you restart Firefox, see How to fix preferences that won't save. '' '''IPv6''' Firefox supports IPv6 by default, which may cause connection problems on certain systems. To disable IPv6 in Firefox: * Type about:config in the address bar and press Enter. * A warning page may appear. Click Accept the Risk and Continue to continue to the about:config page. * In the Search field, enter network.dns.disableIPv6. * In the list of preferences, click the Toggle aboutconfig-ToggleButton button next to network.dns.disableIPv6 to set its value to true. '''DNS Prefetching''' Firefox attempts to speed up loading new websites by using DNS Prefetching, which can cause page load errors with some system configurations. To disable DNS Prefetching: * Type about:config in the address bar and press Enter. * A warning page may appear. Click Accept the Risk and Continue to continue to the about:config page. * Enter the preference name network.dns.disablePrefetch in the about:config search bar. * If the preference doesn't already exist, select Boolean and click the Add aboutconfig-AddButton button. * Press the Toggle aboutconfig-ToggleButton button to set the preference value to true, if it's not already set. ''' for more information vist the below link:''' https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can tell me its help. thank you!

No. None of this is the issue. It was working before. It seems that Firefox decided to wreck that feature for us: https://support.mozilla.org/questions/1293613