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

• https://addons.mozilla.org/firefox/addon/places-maintenance/

See also:

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If you use Sync then best is to disconnect Sync (temporarily) while performing maintenance/repair efforts to the places.sqlite database.

Just an observation in passing. I note the location column is blank in your screenshot

Very recently I saw a blank location column in my bookmarks Library in Fx46.0a the problem resolved itself. I have not seen it again. I did not use places-maintenance to fix the issue. I do not use Sync. I my have lost some recent bookmarks, but have not noticed anything else going wrong.

I just thought I would mention it. It could be nothing more than coincidence. On the other hand there could possibly be some unreported bug. I do not open my bookmarks manager very often so I could go for weeks without noticing something had gone wrong.

Thanks for the reply guys.

I restored my bookmarks from an old backup file which solved the issue but I lost the bookmarks made after the backup file date :(

Mozilla should rectify this problem as soon as possible.