If images are missing then check that you do not block images from some domains. You can tap the Alt key or press F10 to show the Menu Bar Check the permissions for the domain in the currently selected tab in "Tools > Page Info > Permissions"

Check "Tools > Page Info > Media" for blocked images

Select the first image link and use the cursor Down key to scroll through the list. If an image in the list is grayed and "Block Images from..." has a checkmark then remove this checkmark to unblock images from this domain.

Make sure that you do not block (third-party) images, the permissions.default.image pref on the about:config page should be 1.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

There are extensions like Adblock Plus (Firefox menu button/Tools > Add-ons > Extensions) and Anti-Virus software that can block images and other content.

See also:

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• http://kb.mozillazine.org/Images_or_animations_do_not_load
• http://kb.mozillazine.org/Websites_look_wrong

Did you ever use a version of Firefox with Facebook before Firefox 42, with better results?

One of the headline changes in Firefox 42 is adding a tracking blocker in private browsing windows. When something in the page is being blocked, a "shield" icon will appear at the left end of the address bar:

Do you see anything like that?

If you are using private windows, you can turn off the anti-tracking feature on the Options page as a test. This article has more information on where to find that setting: What happened to Tracking Protection?.