That's bad, I wonder whether that is a known issue in Firefox 55?

Have you found any way to recover the lost tabs? I have a tool to extract addresses from a session history file which you can try.

To locate the files:

You can open your current Firefox settings (AKA Firefox profile) folder using either

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

In the first table on the page, click the "Open Folder" button.

In your profile folder, scroll down and double-click into the sessionstore-backups folder. You may want to save the files here to a safe location, such as your Documents folder.

Then you can drag and drop a file onto the box on this page:

https://www.jeffersonscher.com/res/scrounger.html

Do you have any special characters (i.e. non-ASCII) in the file path of the Firefox profile folder?

You can see this path on the about:profiles page under Root Directory. You can open "about:" pages via the location/address bar

• "about:" is a protocol to access special pages

Nope.

jscher2000 said

That's bad, I wonder whether that is a known issue in Firefox 55? Have you found any way to recover the lost tabs? I have a tool to extract addresses from a session history file which you can try. To locate the files: You can open your current Firefox settings (AKA Firefox profile) folder using either

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

In the first table on the page, click the "Open Folder" button. In your profile folder, scroll down and double-click into the sessionstore-backups folder. You may want to save the files here to a safe location, such as your Documents folder. Then you can drag and drop a file onto the box on this page: https://www.jeffersonscher.com/res/scrounger.html

I deleted all the backups already in the process of attempting to troubleshoot.

andygal said

I deleted all the backups already in the process of attempting to troubleshoot.

Can any of them be restored from the Windows 7 "Recycle Bin"?