Are you closing Firefox properly and give it enough time to finish and write all data to the profile folder ?

If you let Windows close Firefox then this can cause issues.

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

See also:

• https://support.mozilla.org/en-US/kb/firefox-starts-automatically-when-i-restart-window

Hello sistokid,

In addition to the above :

Your system details show that your profile folder contains a   user.js   file .....

Would you please take a look at this thread :

https://support.mozilla.org/bm/questions/1255528

Are you closing Firefox properly and give it enough time to finish and write all data to the profile folder ? If you let Windows close Firefox then this can cause issues. 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

---

See also:

• https://support.mozilla.org/en-US/kb/firefox-starts-automatically-when-i-restart-window

Not entirely sure what you mean by letting Windows close it but it doesn't matter what exit method I use, I'm getting the last session every time.

Hello sistokid, In addition to the above : Your system details show that your profile folder contains a   user.js   file ..... Would you please take a look at this thread : https://support.mozilla.org/bm/questions/1255528

I changed the browser.sessionstore.max_resumed_crashes from 1 to 0 as suggested by this post, no difference. As for the user.js file, how do I open it or change it?

You can check if you have a user.js file in the Firefox profile folder that sets the browser.sessionstore.resume_session_once pref to true.

• browser.sessionstore.resume_session_once

You can check its content with a text editor (right-click: "Open with"; do not double-click).
The user.js file is read each time Firefox is started and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

You can delete the user.js file if you didn't create this file yourself.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

I just wound up doing a reinstall. Problem solved. Thanks!!

I just wound up doing a reinstall. Problem solved. Thanks!!

      Thank you for letting us know   -   well done !