• What is it you are tying to do and anything to do with Firefox ?

Maybe it is a faulty key, or some other software is interfering and managing to take control of that combination of key presses.

• Do you only notice this with Firefox ?
• Can you use the combination in Windows, for instance Ctrl+Shift+Esc to open task manager or Ctrl+Shift+Tab in tabbed dialogues
  • http://windows.microsoft.com/en-us/windows/keyboard-shortcuts#keyboard-shortcuts=windows-7

Its working fine in Firefox 23.0 . I think you are unable to Restore session after closing the Browser.Is it So?

Yes is only with Firefox

Nope... Is unable when i close a tab & the browser is still open...

Ok then if it is a Firefox problem try Firefox in safe mode

• Diagnose Firefox issues using Troubleshoot Mode
  • does Ctrl + Shift work now ?
• Keyboard shortcuts are listed here Keyboard shortcuts - Perform common Firefox tasks quickly
  • do the actions work when you use the menu option instead?
    For instance Ctrl+Shift+B in Windows Firefox opens the Library. Can you also do that from the Firefox button
  • see also Use bookmark folders to organize your bookmarks
  • do menu options work only in safe mode or in ordinary mode ?

Problem solved... I uninstall Firefox & i reinstall it & now everything is ok... This is the 1st time that i have problems with Firefox...

Thank you all!!!

1. I uninstall Firefox and reinstall again 2. Other key combinations working. 3. "Keyboard shortcuts - Perform common Firefox tasks quickly" from that link i changed ctrl+shift+t to another key but my problem is not keys.

Undo closed tab still not working :S

Hi CihangirErtem

Which locale are using?

Does undo close tab work from the History menu (History > Recently Closed Tabs/Windows)?

thx cor-el

Finally Solved

Locale was "TR" Turkish. Reinstall at ENG didnt worked. Recomended value 0 but, i set 40 tabs & windows.

In the Location bar, type or paste about:config, press Enter.
If necessary, click I'll be careful, I promise
In the Search box, paste browser.sessionstore.max
Double-click browser.sessionstore.max_tabs_undo, in the prompt, type 0
Double-click browser.sessionstore.max_windows_undo, in the prompt, type 0

The issue is fixed in upcoming Firefox 26.0 and not 25.0/25.0.1

For reading as Bugzilla is not a discussion forum.

Bug 858975 - Shortcut key for Inspector is conflicting with shortcut key for undo close tab

Hello - this is happening to me as well for Firefox 27.0. Help please and thank you :)

Hi Poignant Tuna,

Probably best to start your own thread (As the guidelines suggest).

1. Please use /questions/new
2. Please try to follow the prompts and include troubleshooting info when you do that. (There is a green button to automate the process. Use that, or if you encounter problems doing so mention that in the new thread.)
3. You may wish to post back here; afterwards; to confirm you started a new thread. Others may wish to follow it.

Firefox 27 Beta and no fix yet!!! >:-( Ctrl+Shift+T does NOTHING. GIVE ME MY CLOSED TABS BACK (going to the History menu item is tedious)

Greek locale here, don't know if that's the problem

Ctrl+Shift+T works for me with the Greek locale installed.

Is that shortcut listed in History > Recently Closed Tabs for the first entry?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Delete a possible user.js file and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js

Dear cor-el,

I have restarted in Safe mode and yes, the Ctrl+Shift+T does work again. The shortcut IS listed in "History" > "Recently Closed Tabs" (first entry). Hardware acceleration surely can't be the problem since it's a keyboard, not a display issue..?

I have tens of add-ons (and they are all essential to me). It would be great if you could enable (or disable) them one-by-one without having to restart Firefox every time. I have tens of them so...

It was "Tab Mix Plus" addon's fault, I have installed "development version" (4.1.3) and Ctrl+Shift+T works again.

Sorry for originally accusing Firefox about it...

Thanks cor-el !!!

Related bug reported with activity as recent as today:

https://bugzilla.mozilla.org/show_bug.cgi?id=934231

I have Tabs Mix Plus installed too and reverting back to Firefox 26 from Firefox 27 resolved everything. I didn't need to uninstall any addons.