Please try refreshing Firefox. This will get rid of all extensions and their data. If it doesn't help, try creating a new Firefox profile. Not only extensions, but all user data will be gone with this method, though you are able to switch between profiles, so not really gone. See here for more information about profiles.

I already tried a refresh. That didn't work. New Profile didn't work either. Next idea? Are there settings in about:config I should check?

Try to disable the new Activity Stream design and revert to the earlier design by setting this pref to false on the about:config page.

• browser.newtabpage.activity-stream.enabled

Setting browser.newtabpage.activity-stream.enabled to false got the cog wheel and the web sites to display. So I can get the earlier design to work. Do I just stick to the old design or is there a way to repair and get the new design to work properly?