Are there any errors about this in the Browser or Web Console (Firefox/Tools > Web Developer)?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can check for problems with preferences.

Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.

• http://kb.mozillazine.org/Preferences_not_saved
• http://kb.mozillazine.org/Resetting_preferences

Thank you for the fast response cor-el!

I am not sure how to check for errors in the web console. I moused around within the console on a new empty tab and nothing stood out, but again I have no idea what to look for.

Started in safe mode with no luck. The appearance was already default.

Found only the prefs.js file, no others, and deleted it. Still no luck.

Also you can try entering about:config in your address bar. Search browser.newtabpage.enhanced and double click it to change the value to true. See if that works.

Looks like it is already set to true :(

I also toggled browser.newtab.url to about:blank and then back to about:newtab but no luck there either.