I don't why this question has no answer. I'm still having this issue. I just closed by mistake my main window and upon using ”Recently Closed Windows”, Firefox will open windows FROM A FEW HOURS AGO, not the one CLOSED 10 seconds ago. WHY??? Do I need to answer this in the support channel a million times for someone to answer or fix this?

Usually if you close a non-private window and check the Recently Closed Windows list, that window will be the first available for restoration. I can't think of any explanation for a non-private closed window to be missing from the list after you use its X button.

Unless it was not in the same session of Firefox as the other window. Firefox is capable of maintaining and running in multiple profiles simultaneously. Could you check this:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have another profile here? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

Does that have the missing window?

Hi, jscher2000,

Thanks for responding. I actually have 3 profiles there. I opened hit ”Launch profile in new browser” for 2 of them and I actually got back the tabs from the initial question from 5 months ago. I can't believe it. Could you, please, tell me why this is happening? Why do I have more than 1 account in this section?

Thanks!

One possible reason for multiple profiles is when a profile folder (or critical files) are locked during an update. We've also had some users report a Firefox multi-install, when Firefox was here:

C:\Program Files (x86)\Mozilla Firefox

because they used Firefox since the 32-bit days, and somehow a 64-bit update went instead into the default 64-bit folder rather than doing an in-place update:

C:\Program Files\Mozilla Firefox

Now they have two installs of Firefox that may use separate profiles. If their default profile for external links is in the older folder and their desktop icon opens the Firefox in the newer folder, then they might often end up running two profiles at the same time.

Possibly this happened to you.

Either way, the about:profiles page has buttons to change your default profile so it can be consistent with the one used by your desktop shortcut.

I don't know the best way to detangle/reconcile the different sessions in different profiles. Possibly joining them all to the same Firefox Account and synchronizing tabs might ease the process of letting go of older ones, but I've never tested it myself.

I understand (I actually don't), but you've been really helpful. Thanks again!

Okay, let me mention one other thing. If you run an older version of Firefox that is lurking somewhere on your system, it should object that it can't use an upgraded profile and you need to create a new one or quit. This may help in tracking down and removing an obsolete installation.

Unfortunately, the issue occurs again. I closed my main windows and when I try to restore it, it restored tabs from 2 days ago... I think I have to clean everything Firefox related from my pc, do a clean install and delete all older profiles.

I don't think you need to burn your Firefox to the ground.

When you get the wrong profile launching, check the Troubleshooting Information page to see the install location. If you discover an unwanted install, you can selectively remove that. However, I suggest first making Internet Explorer your default browser at the system level before removing any Firefox installation. You can make Firefox the default again afterwards.

Similar threads:

• https://support.mozilla.org/questions/1293863
• https://support.mozilla.org/questions/1309902

So, after I uninstalled and deleted all things related to Firefox, I reinstalled the latest version. I, once again closed my main window and when reopening recently closed windows, guess what? It still doesn't work. It opens empty windows from god knows when.

If you deleted the program file folders, then after reinstallation, about:profiles should look the same as it did before. If you return to that page, any changes?

If you deleted all your user data, then nothing should have been restored from disk. Maybe from your Firefox Sync account?

You can check for problems with the sessionstore files in the sessionstore-backups folder in the Firefox profile folder that stores session data during the current session.

You will normally find these files in the sessionstore-backups folder:

• previous.jsonlz4 (cleanBackup: copy of sessionstore.jsonlz4 from previous session that was loaded successfully)
• recovery.jsonlz4 (latest version of sessionstore.jsonlz4 written during runtime)
• recovery.baklz4 (previous version of sessionstore.jsonlz4 written during runtime)
• upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox)

Does Firefox update these files during a session ?

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