Firefox has "captive portal" detection to facilitate use of public WiFi hotspots and other networks that require signing in. Apparently Firefox is having trouble reaching its test domain at detectportal.firefox.com and therefore thinks you need to sign in. Here's how you can turn off the captive portal feature: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future. Since we have had this setting for a long time and I use it myself, I feel comfortable mentioning it.'' (2) In the search box in the page, type or paste '''network.captive-portal-service.enabled''' and pause while the list is filtered (3) Double-click the preference to switch the value from true to false