Hello again. Is this before or after the Refresh you did in your other question ?

It was happening before the refresh. The refresh didn't change it.

Working with macs....ahhhh. No easy way of doing stuff. Do you have this issue in other browsers ? Since send info to Mozilla is turned off from within Firefox I do not have info on your drivers for your video card or if there are errors in them. You can inspect this information yourself. u,available is good, un,available is bad. Type about:support in the address bar and press Enter. This will give you info on a bunch of stuff. You can post them if you want us to look at them. But by inspecting the 1st 6in of the video card info will let you know if something is wrong with the drivers, corruption or handled by user settings, or.... A refresh is usually what would suggest. But please try it in : SAFE MODE *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes In Firefox Safe mode these changes are effective: *all extensions are disabled (about:addons) *default theme is used (no persona) *userChrome.css and userContent.css are ignored (chrome folder) *default toolbar layout is used (file: localstore-safe.rdf) *Javascript JIT compilers are disabled (prefs: javascript.options.*jit) *hardware acceleration is disabled (Options > Advanced > General) *plugins are not affected *preferences are not affected TEST'''''''''is issue still there ? If no issues then Extensions which need to be added back in 1 at a time and tested ..... Or it is your Profile : Make a new one and test ...: *https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles If is your Profile : *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox Note: Any customization will revert back to default, you will also need to reinstall Extensions. Please let us know if this solved your issue or if need further assistance.