It feels like I'm the only person who is having this issue.

Sometimes this is true. Only the one reporting an issue has the problem.

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 bar.

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.

How do I access the sessionstore files?

This might not be the issue, but if it keeps happening repeatedly:

There was a bug in Firefox 92-93 related to session history files if the last tab in the session was closed using its X button. (details)

If you are restoring old sessions saved in Firefox 93, and some tabs or all tabs are missing from a window, that window might be permanently corrupted.

I suggest creating a new window (Ctrl+N) and moving the important tabs to the new window, and then closing the permanently corrupted window so you don't accidentally keep using it.

How do I access the sessionstore files?

They are stored in your currently active Firefox profile folder. This article has the details on how to open that folder in Windows' File Explorer: Profiles - Where Firefox stores your bookmarks, passwords and other user data.

The files are compressed and won't be readable unless you decompress them. That's the purpose of my page at https://www.jeffersonscher.com/ffu/scrounger.html. After you drop the file on the box, a script in the page decompresses it and shows its contents. These are a tightly packed data format called JSON which is a little hard to read. If you click the "Scrounge URLs" button another script generates a readable list of open and closed windows and tabs found in the file. You can use the "Save List" button to save it as an HTML file (web page) on your computer for future reference.

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

Where do I find the file?

I've been slowly working through all of these that people post and no results so far.

I thank all of you though

Where do I find the file?

Is that a different question than the one I answered earlier:

mmccrackentljj said

How do I access the sessionstore files?

They are stored in your currently active Firefox profile folder. This article has the details on how to open that folder in Windows' File Explorer: Profiles - Where Firefox stores your bookmarks, passwords and other user data.

The files are compressed and won't be readable unless you decompress them. That's the purpose of my page at https://www.jeffersonscher.com/ffu/scrounger.html. After you drop the file on the box, a script in the page decompresses it and shows its contents. These are a tightly packed data format called JSON which is a little hard to read. If you click the "Scrounge URLs" button another script generates a readable list of open and closed windows and tabs found in the file. You can use the "Save List" button to save it as an HTML file (web page) on your computer for future reference.