Recent answers to What happened to the "undo close tab" feature in FF 4?https://support.mozilla.org/en-US/questions/8162932011-05-14T21:12:53-07:00Never mind, I found it. For future reference, in case anyone else has this problem, it was Blackshee2011-05-14T21:12:53-07:00anaximanderhttps://support.mozilla.org/en-US/questions/816293#answer-183764<p>Never mind, I found it. For future reference, in case anyone else has this problem, it was Blacksheep that was causing it. I'm going to disable Blacksheep and tell the developers; hopefully they'll fix it and put out an update.
</p>Progress! It works with all my addons disabled. Now to enable them one at a time until it stops work2011-05-14T20:52:42-07:00anaximanderhttps://support.mozilla.org/en-US/questions/816293#answer-183760<p>Progress! It works with all my addons disabled. Now to enable them one at a time until it stops working again, and then work out why that particular addon has broken it. Unless anyone has a faster way?
</p>Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions i2011-05-14T11:55:59-07:00cor-elhttps://support.mozilla.org/en-US/questions/816293#answer-183616<p>Start Firefox in <u><a href="/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode" rel="nofollow">Diagnose Firefox issues using Troubleshoot Mode</a></u> to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) &gt; Add-ons &gt; Appearance/Themes).
</p>
<ul><li> Don't make any changes on the Safe mode start window.
</li><li> <a href="https://support.mozilla.com/kb/Safe+Mode" rel="nofollow">https://support.mozilla.com/kb/Safe+Mode</a>
</li></ul>
<ul><li> <a href="/en-US/kb/troubleshoot-extensions-themes-to-fix-problems" rel="nofollow">Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems</a>
</li></ul>Session restore is on, max_tabs_undo is set to 10, max_windows_undo is set to 3, and resume_from_cra2011-05-14T10:34:09-07:00anaximanderhttps://support.mozilla.org/en-US/questions/816293#answer-183578<p>Session restore is on, max_tabs_undo is set to 10, max_windows_undo is set to 3, and resume_from_crash is on. I'm not in Private Browsing mode, and the Privacy page says Firefox will: remember history - I selected custom and checked, Permanent Private Browsing mode is off, it's set to remember everything. Still can't reopen closed tabs or windows.
</p>Check that session restore is enabled.
http://kb.mozillazine.org/Session_Restore
You can also che2011-05-14T09:54:48-07:00cor-elhttps://support.mozilla.org/en-US/questions/816293#answer-183556<p>Check that session restore is enabled.
</p>
<ul><li> <a href="http://kb.mozillazine.org/Session_Restore" rel="nofollow">http://kb.mozillazine.org/Session_Restore</a>
</li></ul>
<p>You can also check these prefs on the <a href="http://kb.mozillazine.org/about:config" rel="nofollow">about:config</a> page.
</p>
<ul><li> <a href="http://kb.mozillazine.org/browser.sessionstore.max_tabs_undo" rel="nofollow">http://kb.mozillazine.org/browser.sessionstore.max_tabs_undo</a>
</li><li> <a href="http://kb.mozillazine.org/browser.sessionstore.max_windows_undo" rel="nofollow">http://kb.mozillazine.org/browser.sessionstore.max_windows_undo</a>
</li><li> <a href="http://kb.mozillazine.org/browser.sessionstore.resume_from_crash" rel="nofollow">http://kb.mozillazine.org/browser.sessionstore.resume_from_crash</a>
</li></ul>
<hr>
<p>Make sure that you not run Firefox in (permanent) <a href="/en-US/kb/private-browsing-use-firefox-without-history" rel="nofollow">Private Browsing - Use Firefox without saving history</a> mode.
</p>
<ul><li> You enter Private Browsing mode if you select: Tools &gt; Options &gt; Privacy &gt; History: Firefox will: "Never Remember History"
</li><li> To see all History and Cookie settings, choose: Tools &gt; Options &gt; Privacy, choose the setting <b>Firefox will: Use custom settings for history</b>
</li><li> Uncheck: [ ] "Permanent Private Browsing mode"
</li></ul>Downloaded, installed, doesn't work either. It says there are no closed tabs to reopen, despite the 2011-05-14T09:21:32-07:00anaximanderhttps://support.mozilla.org/en-US/questions/816293#answer-183544<p>Downloaded, installed, doesn't work either. It says there are no closed tabs to reopen, despite the fact that I opened and closed several just seconds previously to test it. It seems to be a deeper issue with Firefox not remembering tab closes.
</p>anaximander -- If nothing works, you can always use this add-on:
https://addons.mozilla.org/en-US/fi2011-05-14T01:46:16-07:00silkphoenixhttps://support.mozilla.org/en-US/questions/816293#answer-183376<p>anaximander -- If nothing works, you can always use this add-on:
</p><p><a href="https://addons.mozilla.org/en-US/firefox/addon/undo-closed-tabs-button/" rel="nofollow">https://addons.mozilla.org/en-US/firefox/addon/undo-closed-tabs-button/</a>
</p>Similar issue here - my browsing history is being saved correctly, but the options for Restore Previ2011-05-14T01:38:59-07:00anaximanderhttps://support.mozilla.org/en-US/questions/816293#answer-183372<p>Similar issue here - my browsing history is being saved correctly, but the options for Restore Previous Session, Recently Closed Windows and Recently Closed Tabs are all greyed out, no matter how many windows or tabs I've opened and closed. Right-clicking on an active tab give a whole load of options, none of which say "Undo Close Tab" or anything vaguely like it. It's annoying, because this was a REALLY useful feature.
</p>The Undo closed tab can be used as on previous FF3.x's
But ( I know I shouldn't start with a but, bu2011-05-13T13:00:46-07:00mykhillhttps://support.mozilla.org/en-US/questions/816293#answer-183140<p>The Undo closed tab can be used as on previous FF3.x's
But ( I know I shouldn't start with a but, but....) FireFox 4.x
has the same "last one undo" from a right click on any tab.
It has also been improved hugely on the History dropdown.
At the bottom of the dropdown are TWO selections showing
"Recently closed tabs" and "Recently closed windows".
Both alow a selection from a list, not just the last.
</p>@bjbayer, Undo Close Tab should work if there is tab history in the current window. If you check und2011-05-06T08:31:23-07:00jscher2000https://support.mozilla.org/en-US/questions/816293#answer-178689<p>@bjbayer, Undo Close Tab should work if there is tab history in the current window. If you check under
</p><p>History &gt; Recently Closed Tabs
</p><p>is anything listed? If not, have you set Firefox not to remember history??
</p>I have the same problem, but can't solve it by looking for the right click option. When I right clic2011-05-06T08:23:38-07:00bjbayerhttps://support.mozilla.org/en-US/questions/816293#answer-178679<p>I have the same problem, but can't solve it by looking for the right click option. When I right click on an active tab, I see "Undo close tab," but it's grayed out. This only started happening with 4.0.1.
</p>Lol, brilliant failure on my part. With the update, for some reason it won't offer up the "undo clo2011-05-01T14:30:58-07:00JetAngelhttps://support.mozilla.org/en-US/questions/816293#answer-176023<p>Lol, brilliant failure on my part. With the update, for some reason it won't offer up the "undo closed tab" option unless I click on an already active tab. Thank you!
</p>In Windows, we do one of these:
right-click any tab and choose from the context menu (works when tw2011-05-01T11:56:05-07:00jscher2000https://support.mozilla.org/en-US/questions/816293#answer-175917<p>In Windows, we do one of these:
</p><p>right-click any tab and choose from the context menu (works when two or more tabs are open, or you always display tabs)
</p><p>Ctrl+Shift+t
</p><p>History &gt; Recently Closed Tabs
</p><p>Is there anything like that on MacOS?
</p><p>---
</p><p>Just noticed someone created an add-on to create a toolbar button for the recently closed tabs list: <a href="https://addons.mozilla.org/en-US/firefox/addon/undo-closed-tabs-button/" rel="nofollow">Undo Closed Tabs Button&nbsp;:: Add-ons for Firefox</a>. (I haven't tried it myself.)
</p>