The way the bookmarks file is set up is different with those versions. First, export the bookmarks from v63, then import them to v56. Before importing the file, delete the '''places.sqlite''' file in v56. +++++++++++++++++++++++++++++++++++++++++++++++ Type '''about:support'''<enter> in the address bar. Under the page logo on the left side, you will see '''Application Basics. ''' Under this find '''Profile Folder. ''' To its right press the button '''Show Folder. ''' This will open your file browser to the current Firefox profile. Now '''Close Firefox. ''' Locate the above file. Then rename or delete it. Restart Firefox. +++++++++++++++++++++++++++++++++++++++++++++ Open the '''Bookmarks Manager; ''' Press the '''Alt''' or '''F10''' key to bring up the toolbar, and select '''Bookmarks. ''' Hot key is '''<Control> ''(Mac=<Command>)'' <Shift> B. ''' Once the window is open, at the top of the page, press the button labeled ''' Import and Backup. ''' Select '''Export''' '''Bookmarks To HTML, ''' and follow the prompts and save it to a '''HTML''' file. '''Copy''' the file to another computer/profile. Repeat the instructions above, BUT select '''Import Bookmarks From HTML. ''' https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks