Can you delete the bookmark in the Bookmarks Manager (Library)? * Bookmarks > Show All Bookmarks *https://support.mozilla.com/kb/Deleting+Bookmarks ---- If that doesn't work then there may be 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.com/kb/Bookmarks+not+saved#w_places-database-file