Hi David, that's odd.

Can you think of any process that might run at system startup which would modify Firefox's session history? Here's the context:

Normally, when it shuts down, Firefox creates a file named sessionstore.jsonlz4. At the next startup, Firefox uses that file to make the "Restore Previous Session" option available. If any program were to remove that file, then when Firefox starts up, it will look for older files, and possible restore one automatically, thinking it needs to recover from a crash. So for example, if you have any utility or privacy software set to clean up browser data at system startup, that would be a potential explanation.

As an experiment, let's hide Firefox's old session history files to rule out that scenario. Here's how:

(1) Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Show in Finder" button. If Finder highlights an icon with a semi-random name like a1b2c3d4.default, double-click it to display the contents of that profile folder.

(2) Leaving that window open, switch back to Firefox and Quit, either:

• "3-bar" menu button > Quit
• (menu bar) Firefox > Quit

Note, I'm a Windows user, so these are guesses about your menus!

(3) Pause while Firefox finishes its cleanup, then rename the sessionstore-backups folder to something like sessionstore-backupsOLD

When Firefox starts up again, it should create a new folder that only contains open tab data for your current session.

Any difference at the next system startup?

I did as you suggested, but the behavior is the same. ???

After reading your suggestion, it occurred to me that when I purchased some Amazon home automation switches I attempted to program them with my laptop, but this was unsuccessful and I had to use their app on my iPhone instead, which was successful. I have found something called "iAlexa" with a finder search and deleted just now. I will quit Firefox, log out, and log back in and see what happens.

Wow. That fixed it. I don't know what "iAlexa" is, but deleting it solves the problem. Thanks for your help. David.