Firefox installed an update on my Macbook pro today but failed to restore my previously open window.

Hi,

Please see How to restore a browsing session from backup.

Hi, Thank you for the response. I've updated my Macbook pro (M2) to Tahoe 26.5, but when Firefox installs a new update after I quit it, my open tabs and windows are not restored. This despite the fact I have the option to restore tabs and windows selected. How can I stop this from happening? It's a recent bug and if I cannot easily solve this I will be forced to abandon Firefox.

Further update. I'm using v151.3 and if I quit Firefox and restart, my previously open tabs and windows don't reopen. Moreover, the option to "restore previous session" is greyed out. My impression is that this issue has to do with the introduction of profiles. I could use some help here.

Quoting from that article, the tricky ones that might be getting in the way, and are worth checking, and perhaps even setting on and then back off, are in these steps:

•  Check history settings
•  Select the Privacy & Security panel.
• In the History section make sure that the "Firefox will…" drop-down menu is set to either "Remember history" or "Use custom settings for history".
• If "Firefox will…" is set to "Use custom settings for history", then make sure that "Always use Private Browsing mode" is not checked.
•  If "Firefox will…" is set to "Use custom settings for history" and "Clear history when Firefox closes" is checked, then click the Settings button and make sure that "Browsing & download history" is not checked.

Other than that:

Try disabling the "restore tabs…" option, restart, enable again, restart, see if there's any difference.

If it still doesn't seem to "stick", consider creating a new temporary profile just to test, and see if the setting to "restore tabs…" has effect there. If it does, try switching back to your original profile and see whether that one sticks now as well or not.

I just checked the history section after posting a query to an AI chatbot; it was set to clear history on exit . I changed the setting and it solved the problem! Thanks.

Great! Thanks for letting us know!