You can toggle DRM off/on to see if that makes Firefox (re)load DRM components. *Settings -> General: Digital Rights Management (DRM) Content *https://support.mozilla.org/en-US/kb/enable-drm You can check the connection settings and check for possible issues with a Proxy or VPN service. *Settings -> General -> Network: Connection -> Settings If you do not need to use a Proxy to connect to internet, select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly. See also: *https://support.mozilla.org/en-US/kb/connection-settings-firefox *https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors You can create a new profile as a quick test to see if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles If the new profile works, you can transfer files from a previously used profile to the new profile, but be careful not to copy corrupted files to avoid carrying over problems. *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Huh, the new profile worked! Thank you. But, how do I know what file caused the corruption so I don't copy it over?