What do you mean with the pin button? Do you mean the icon that appears if you hover a slot on the about:newtab page to pin a URL to the current slot? The thumbnails on the about:newtab page are generated from the cache, so if the page is not in the cache or otherwise can't be rendered as a PNG image then you will get an empty box.<br /> Do not use Clear Recent History to clear data when you close Firefox.<br /> If there is no history then you get an about:newtab page with empty boxes. ---- A possible cause is a problem with the file places.sqlite that stores the bookmarks and the history. *http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox *https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file You can also try to repair the places database with this extension: *https://addons.mozilla.org/firefox/addon/places-maintenance/