First, check this setting: https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

If the browser crashed or did not close properlly, it will restore the last session. This is how the browser is set up.

Make sure you close the browser using; Windows: Menu > File > Exit Mac: Menu > Firefox > Quit Firefox Linux: Menu > File > Quit

Some users have reported issues when closing the browser using the X upper-right of the window.

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.

Can't find any sessionstore files. Using windows 8.1. Where would they be? Also, there is no page logo on the left side. Can you be more specific?

Looks like they took it out. Under Troubleshooting Information on the left side . . .

I deleted the sessinstore backup folder. There were no other sessionstore files. I moved the sessionCheckpoints.json file to the desktop. Got out of Firefox and restarted it. Still opened to session restore

I wound up uninstalling and reinstalling FireFox. That's the only thing that worked.

That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems. Go to that post and click the 'Solved' button to its right.

It is odd the problem was fixed by a re-install. But, whatever works. Note: Firefox v97 just came out.

There is no button solved problem or chosen solution

That response has been flagged as the solution.

Update...the restore session nonsense is back again! If Mozilla doesn't fix this I'm going to have to move to a different browser.

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

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

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address box.