I found the answer. It deletes all bookmarks but I didn't care at this point. [http://support.mozilla.com/en-US/kb/bookmarks+not+saved] Find the location of your places preferences and reset them as directed. Then, follow the steps under '''Places database file''' to delete these files (I suppose you could just rename them but I didn't try it): ''places.sqlite'' file and, if it exists, ''places.sqlite-journal'' (Optional) Also delete the file ''localstore.rdf'' I was then able to restart Firefox and deleted the imported bookmark folders.