If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (Adblock Plus, NoScript, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block (wanted) content. *make sure your extensions and filters are updated to the latest version *https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems Firefox shows the shield icon at the left end of the location/address bar in case content is blocked by Tracking Protection. *click the shield icon for more detail and possibly disable the protection *check the Web Console for more detail about what content is blocked by Tracking Protection *"3-bar" menu button or Tools -> Web Developer *https://support.mozilla.org/en-US/kb/tracking-protection-firefox You can check the Web Console for messages about blocked content. *"3-bar" menu button or Tools -> Web Developer *https://developer.mozilla.org/en/Tools/Web_Console