I performed all the remedies detailed in Help to restore the Favorites button to the Bookmarks Toolbar, but to no avail. The Favorites button is still missing from my Bookmarks Toolbar. It disappeared last evening when some cosmetic changes appeared on my Navigation bar. I earlier had imported my Favorites from Internet Explorer, but they are buried deep in the Bookmarks menu, and do not permit of adding a new Favorite -- so aren't practical to use. If I could sync my Favorites to my Bookmarks, I could finally abandon the Favorites in favor of the Bookmarks -- but apparently Firefox does not allow for such possibility. Disappearance of the Favorites button from the Bookmarks Toolbar makes Firefox all but unusable for me -- unless I can find a solution. I have no add-ons, and no new plugins that might be causing this problem.