*https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data Profile : Make a new one and test ...: then..... *https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox *https://support.mozilla.org/en-US/kb/import-bookmarks-html-file If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem. Never work with original files. Please let us know if this solved your issue or if need further assistance.

Don't you see any of the imported bookmarks in the Bookmarks Manager (Library)? Do you otherwise have issues with bookmarks or history?