https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

Refresh Firefox {web link} is a LAST RESORT ! !

Refresh Firefox - reset add-ons and settings

If you're having problems with Firefox, refreshing it can help. The refresh feature fixes many issues by restoring Firefox to its default state while saving your essential information like bookmarks, passwords, and open tabs.

Places Maintenance {web link} Allows to run Maintenance tasks on the database that drives Places, the bookmarks and history module behind Firefox.

Open the Add-ons Manager. Locate the add-on and press the Options button. Then follow the directions.

You can delete the places.sqlite file to remove all the history.

You can use this button to go to the current Firefox profile folder:

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

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

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

Thanks everyone! I appreciate the advice :)

Has your problem been solved?

Expire history by days {web link} Allows to expire history older than a fixed amount of days.