Hi, suggest you update to 61.0esr as the 52 will update to 60 then will match version numbers after that in September.

If do not want to do above and a Refresh did not fix the issue it maybe in your profile : Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• 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

Maybe that was fixed in ESR 52.9.0 which came out last week.

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page

See also:

• http://kb.mozillazine.org/Locked_or_damaged_places.sqlite
• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page cannot repair places.sqlite then remove all places.sqlite files in the Firefox profile folder. Firefox will rebuild places.sqlite and restore the bookmarks from a recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I solved the failure to set new bookmarks by going to the menu, then "?", then "Troubleshooting," then "Open Directory", then deleting places.*, then restarting Firefox.