It doesn't work at all or you mean you can't restore tabs from the FF70 session that had to close to restart and install 71? Just narrowing things down.

You aren't using permanent Private Browsing mode (Always use Private Browsing mode; Never Remember History) ?

• https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history

Do these prefs still have the default value if you check this on the about:config page?

• browser.sessionstore.max_tabs_undo
• browser.sessionstore.max_windows_undo

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Does Firefox update the files in the sessionstore-backups folder folder ?

Backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running.

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)

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file (make sure to backup the current sessionstore.jsonlz4).

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: Show Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles

cor-el said

You aren't using permanent Private Browsing mode (Always use Private Browsing mode; Never Remember History) ?

• https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history

Do these prefs still have the default value if you check this on the about:config page?

• browser.sessionstore.max_tabs_undo
• browser.sessionstore.max_windows_undo

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

---

Does Firefox update the files in the sessionstore-backups folder folder ?

Backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running.

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)

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file (make sure to backup the current sessionstore.jsonlz4).

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: Show Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles

Hi cor-el and evhenry

Thank you very much for your long reply. I am no expert and unfortunately dont understand what you are describing with so much effort and details.

I just want to explain, that I dont try to restore the 400 closed tabs. (I just mentioned it because I was wondering if others also had this problem after the update).

All I would like to know is how I can restore a tab (immediately resp. in the same session) after closing the tab. I always did this with CTRL+SHIFT+T (it was restoring about up to 10 tabs). But that does not work anymore (since the update). CAN I RE-ACTIVATE CTRL+SHIFT+T OR IS IT NOW A DIFFERENT KEY COMBINATION?

You should either see the recently closed tab history in the History menu on the menu bar or in the History sub menu via the Library button on Navigation Toolbar or via the Library item in the "3-bar" Firefox menu button drop-down list). If the "History -> Recently Closed Tabs/Windows" is empty then there is a problem with sessionstore and you either do not keep history or this feature is disabled like I posted above.

Hi Cor-El

Yes, I see the history. https://gyazo.com/e2c406bb7f502716c7a807b44adfaedb

=> Since it seems, that the problem is not the missing history, what else could it be?

=> Does CTRL+SHIFT+T is still work for you (with 71.0 64-bit)?

(I have Windows 7 Professional. I know it's old and not supported anymore. But I love it.)

=> Did your open tabs also get lost with the latest update?

P.S. Already learned some technical terms from you: "menu bar", "navigation toolbar", "library button", "3 bars menu button". To know this terminology should help to understand future explanations.

evhenry said

It doesn't work at all or you mean you can't restore tabs from the FF70 session that had to close to restart and install 71? Just narrowing things down.

If I close a tab, CTRL+SHIT+T does not bring it back seconds later.

=> Does CTRL+SHIFT+T still work for you (with 71.0)?

=> Did your open tabs also get lost with the latest update?

Mark said

Yes, I see the history. https://gyazo.com/e2c406bb7f502716c7a807b44adfaedb

It's a problem that Recently Closed Tabs is grayed out on the History menu in your screenshot. If that is grayed out, Firefox does not remember any tabs you closed in that window, and Ctrl+Shift+t has nothing to do.

Could you double-check this setting:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste sess and pause while the list is filtered

(3) If the browser.sessionstore.max_tabs_undo preference is bolded and does not have a good-sized value, use the arrow button at the far right end of the bar to restore the default value of 25 or double-click to set the value you prefer

jscher2000 said

Mark said

Yes, I see the history. https://gyazo.com/e2c406bb7f502716c7a807b44adfaedb

It's a problem that Recently Closed Tabs is grayed out on the History menu in your screenshot. If that is grayed out, Firefox does not remember any tabs you closed in that window, and Ctrl+Shift+t has nothing to do.

Could you double-check this setting:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste sess and pause while the list is filtered

(3) If the browser.sessionstore.max_tabs_undo preference is bolded and does not have a good-sized value, use the arrow button at the far right end of the bar to restore the default value of 25 or double-click to set the value you prefer

Dear jscher2000

You have been right: max tabs undo and max windows undo had the value 0 (!)

I filled in the numbers I wish and now CTRL+SHIFT+T works.

But still see two more lines which I could reset: https://gyazo.com/c1d5c6ca9b1b6049379eac269cd29ec6

=> Should I leave it as it is or reset as well?

=> Why was updating to 71.0 altering many Firefox settings? It seems to me, since nobody replied "I have the same problem", that most people had no problems with updating. And frankly said, it is also for me the first time that updating Firefox was a catastrophe.

P.S. => Would it make sense to check if in about:config is more stuff to reset?

Note that checking this pref on the about:config page was one of the suggestions I posted above. I see you changed the pref to 100.

The older bold pref in the screenshot is about storing cookie data for open tabs in the sessionstore.jsonlz4 file as part of session data that will be restored on a next Firefox start.

• browser.sessionstore.privacy_level
  [0:everywhere, 1:unencrypted sites, 2:nowhere]

cor-el said

Note that checking this pref on the about:config page was one of the suggestions I posted above. I see you changed the pref to 100. The older bold pref in the screenshot is about storing cookie data for open tabs in the sessionstore.jsonlz4 file as part of session data that will be restored on a next Firefox start.

• browser.sessionstore.privacy_level
  [0:everywhere, 1:unencrypted sites, 2:nowhere]

I am now aware that you suggested this as first person. You posted to links with leghy explanation and your post was full of technical stuff. I am afraid that I did not understand it.

My questions to you then skipped your attention.