Hi Raindr0p, your Firefox is restoring the correct open tabs -- as expected -- but also re-opening tabs that had been closed long before you Quit?

That's very strange. Normally, Firefox updates your session history file as often as every 15 seconds, so what gets restored should very closely match the last status of open and closed tabs. The closed tabs should be listed on the History menu (each window has its own Recently Closed Tabs list) but not re-opened automatically. What is going on??

Can we rule out a multiple home tab problem? This article points to where you can check your home page setting -- the Custom URLs field can hold a lot of URLs: How to set the home page.

Can we rule out any add-on issues -- you don't use any session-related add-ons? You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Command+Shift+a (Windows: Ctrl+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. On the right side, find the "Manage Your Extensions" heading.

If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:

Do you see anything related to sessions below this heading? If you're not sure what an extension does, disable it (click it "on-off" switch). Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. For your privacy and security, don't let mystery programs linger here.

I've taken a closer look to all extensions (no 'unexpected ones' present), toggled them all off and on and the problem persisted. Given, there were no extensions clearly influencing sessions.

Concerning a possible multiple home tab problem: my home tab is set to the default 'Firefox home', so I don't expect this to be a problem. To be on the safe side, I have reset this.

While investigating the problem, I noticed that my initial conclusion (that all tabs would reopen) should be refined: only a few tabs will reopen. In more detail:

I have two windows open ('w1' & 'w2'), each with a few tabs. When closing the browser and reopening, there are three tabs that persist and will always open (in w2). This has been the case for at least a few days and possibly starting from installation. In w1, there are generally a few extra unwanted/previously closed tabs that reappear at restart, however after closing them & restarting the browser several times, some of them have disappeared (i.e. they will not reappear) while one or two 'new ones' might join this problem.

So far, I have had a look through all settings that might have to do something with this (cookies & site data, history, etc.) but I have yet to find anything that changes the problem....

You can check for problems with the sessionstore.jsonlz4 file in the Firefox profile folder that stores session data.

• delete sessionstore.jsonlz4 and sessionstore.js

When sessionstore.jsonlz4 is deleted you lose pinned tabs and open tabs and you will have to recreate them, so if necessary make a note or bookmark them. sessionstore.jsonlz4 is only present in the Firefox profile folder when Firefox is closed.

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