Are/were you using Private Browsing? If so, history would not be recorded. Profile data can be removed or not recorded in several ways; * 1) Running Firefox in Private Mode (nothing is recorded) * 2) Privacy settings; (In the address box, type '''about:preferences#privacy'''<enter> in the address box. * 3) Many disk cleaners and anti-virus type programs can remove data from browsers<br>Open their settings and have them leave the browsers alone. * 4) Mal-ware. ------------------ You may have corrupt '''sessionstore''' [v56] '''sessionstore.jsonlz4''' file(s). Delete all '''sessionstore*''' files and the '''sessionstore-backups''' folder. '''Don't delete the files''' if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html Type '''about:support'''<enter> in the address box. 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. ''' Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder '''Linux: ''' Under the page logo on the left side, you will see '''Application Basics.''' Under this find '''Profile Directory. ''' To its right press the button '''Open Directory. ''' Locate the above file. Then rename or delete it. Restart Firefox.