Pinned tabs disappear

Hi Firefox Clean B, did you want help with this problem?

I. Did this just happen recently? If so, have you tried to recover the closed windows?

By default, Firefox can re-open up to 3 closed windows from a restored session.

First check whether either of these are available (not hidden or grayed out):

If they are missing or grayed, check either:

If that doesn't help, perhaps there is an old session history file that contains the missing tabs. You need to check ASAP because Firefox constantly replaces these files:

Do not exit Firefox, or if you closed it, don't re-open it.

(1) To open your profile folder...

If Firefox is still running:

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

In the first table on the page, click the "Open Folder" (or "Show in Finder") button.

If Firefox is closed:

Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer:

In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated.

(2) Copy out session history files

In your profile folder, double-click into the sessionstore-backups folder. Save all files here to a safe location such as your Documents folder.

(3) What files did you find?

The kinds of files you may find among your sessionstore files are:

To preview the contents of a file, you can drag and drop it onto the following page on my website, then click the Scrounge URLs button:

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

A script in the page will list all the windows and tabs it finds. If it doesn't finish in 15 seconds, the tab may have crashed. Close it and try again.

If you find useful data, use the Save List button to download that list of clickable links as a web page to your computer for future reference.

II. Have you considered using an add-on as a second level of session history storage?

Thinking toward the future, these are the session management extensions I'm aware of that you might investigate/try out:

Use database storage:

Use bookmark storage:

Bookmark storage is more robust in that Firefox backs it up regularly. However, having the extra data show up when you are searching your bookmarks may be annoying.