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Firefox 25.0.1 Warn when closing multiple tabs (on) conflicts with "show windows und tabs from last time" (on); need both, but only one or the other works.

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  • Last reply by John99

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Using Firefox 25.0.1 on Windows 7 Home Premium

I've poured through support forums for Mozilla Firefox searching for a fix to my initial problem of the "Warn when closing multiple tabs" pop up not popping up when I have it selected.

Went through About:Config, making sure warnings for tabs und closing, und showing on quit, und quitting, etc. were all set to true, which were "possible" fixes for the issue I was having, there are like five or six things set to true for warnings/quitting/etc. No avail. They are all set to true.

Then I stumbled across one that suggested a conflict with the "Warn When Closing Multiple Tabs" und the "Show Windows und Tabs from last time".

I use both features. However, I found if I want the warning pop up for closing multiple tabs, I have to have "show homepage" or "show blank page" selected instead of "Show windows und tabs from last time" selected. (Tools>Options>General>Start Up>When Firefox Starts:) The problem with this is, yes, I get my warning pop up, BUT, I don't get my tabs from my last session.

The warning in settings (Tools>Options>Tabs>Warn Me When Closing Multiple Tabs) is checked.

To have my tabs restored from last session, I simply select it for "when firefox starts". Bam, I have my tabs that were open from the last time I quit. Und again, full circle, I don't have my warning pop up.

There were also suggestions of the warning on close for tabs is conflicting with add-ons.

However, I don't have many. Und I have yet to test them to see if they interfere. These are according to my Add Ons tab when I check it myself.

Extensions: 1. Avast WebRep (disabled) 2. HP Smart Web Printing (disabled)

Plugins: 1. Adobe Acrobat 2. Google Update 3. iTunes Application Detector 4. Java (TM) Platform SE 7 U45 5. Shockwave Flash 6. Shockwave For Director 7. Silverlight Plug-In 8. VLC Web Plugin 9. Windows Live Photo Gallery 10. Java Deployment Toolkit (disabled)

Note: The Details Firefox provides says I have these for Plugins

  • Shockwave Flash 11.9 r900
  • Adobe Shockwave for Director Netscape plug-in, version 12.0.5.146
  • Next Generation Java Plug-in 10.45.2 for Mozilla browsers
  • Google Update
  • Adobe PDF Plug-In For Firefox and Netscape 11.0.05
  • VLC media player Web Plugin 2.1.0
  • 5.1.20913.0
  • iTunes Detector Plug-in
  • NPWLPG

Unsure of what the "5.1.20913.0" und the "NPWLPG" plugins are, but they don't appear to me under Add Ons.

Und as usual, I'm assuming the solution lies within About:Config, I will show here now what I have set to True.

browser.tabs.warnOnClose - True browser.tabs.warnOnCloseOtherTabs - True browser.tabs.warnOnOpen - True browser.warnOnQuit - True browser.showQuitWarning - True

As aforementioned: The seemingly only issue is the conflict between Show Windows/Tabs From Last Time und the Warn On Quit pop up. Und again, I need/want both of them. More so the tabs from the last session, but I really really really really really want the warning.

So, if anyone knows a work around, preferably without having to download anything to fix this, I would be extremely grateful.

Using Firefox 25.0.1 on Windows 7 Home Premium I've poured through support forums for Mozilla Firefox searching for a fix to my initial problem of the "Warn when closing multiple tabs" pop up not popping up when I have it selected. Went through About:Config, making sure warnings for tabs und closing, und showing on quit, und quitting, etc. were all set to true, which were "possible" fixes for the issue I was having, there are like five or six things set to true for warnings/quitting/etc. No avail. They are all set to true. Then I stumbled across one that suggested a conflict with the "Warn When Closing Multiple Tabs" und the "Show Windows und Tabs from last time". I use both features. However, I found if I want the warning pop up for closing multiple tabs, I have to have "show homepage" or "show blank page" selected instead of "Show windows und tabs from last time" selected. (Tools>Options>General>Start Up>When Firefox Starts:) The problem with this is, yes, I get my warning pop up, BUT, I don't get my tabs from my last session. The warning in settings (Tools>Options>Tabs>Warn Me When Closing Multiple Tabs) is checked. To have my tabs restored from last session, I simply select it for "when firefox starts". Bam, I have my tabs that were open from the last time I quit. Und again, full circle, I don't have my warning pop up. There were also suggestions of the warning on close for tabs is conflicting with add-ons. However, I don't have many. Und I have yet to test them to see if they interfere. These are according to my Add Ons tab when I check it myself. Extensions: 1. Avast WebRep (disabled) 2. HP Smart Web Printing (disabled) Plugins: 1. Adobe Acrobat 2. Google Update 3. iTunes Application Detector 4. Java (TM) Platform SE 7 U45 5. Shockwave Flash 6. Shockwave For Director 7. Silverlight Plug-In 8. VLC Web Plugin 9. Windows Live Photo Gallery 10. Java Deployment Toolkit (disabled) Note: The Details Firefox provides says I have these for Plugins * Shockwave Flash 11.9 r900 * Adobe Shockwave for Director Netscape plug-in, version 12.0.5.146 * Next Generation Java Plug-in 10.45.2 for Mozilla browsers * Google Update * Adobe PDF Plug-In For Firefox and Netscape 11.0.05 * VLC media player Web Plugin 2.1.0 * 5.1.20913.0 * iTunes Detector Plug-in * NPWLPG Unsure of what the "5.1.20913.0" und the "NPWLPG" plugins are, but they don't appear to me under Add Ons. Und as usual, I'm assuming the solution lies within About:Config, I will show here now what I have set to True. browser.tabs.warnOnClose - True browser.tabs.warnOnCloseOtherTabs - True browser.tabs.warnOnOpen - True browser.warnOnQuit - True browser.showQuitWarning - True As aforementioned: The seemingly only issue is the conflict between Show Windows/Tabs From Last Time und the Warn On Quit pop up. Und again, I need/want both of them. More so the tabs from the last session, but I really really really really really want the warning. So, if anyone knows a work around, preferably without having to download anything to fix this, I would be extremely grateful.

All Replies (13)

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browser. windows. loadOnNewWindow make sure that is set to 2 in order to launch the previously opened session the last time you closed.

As for the warning not showing up with those set to true:

browser.tabs.warnOnClose - True browser.tabs.warnOnCloseOtherTabs - True browser.tabs.warnOnOpen - True browser.warnOnQuit - True browser.showQuitWarning - True

That should have the warning. From Firefox>Preferences>General Tab Please make sure that on open "show tabs from last time" is selected. However if you want both, that is weird they are not.

Maybe there is another option link.open, newtab, newwindow, open_newwindow, openintab, .tabs., windowopen I will try to reproduce.

This reference of all about:config entries can be looked up here if anything is ever changed and you need a reference. [About:config entries] MozillaZine About:config entries fixed link ~J99

Modified by John99

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I tried to reproduce and the warning only is not there when I select File>exit

Are you closing Firefox with the red x or file exit?

Modified by guigs

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I use the red "x". I never use the file exit to exit. I've already tried the stuff in Tools > Options. So, I thank you for looking into it. I've pretty much given up on the trying to have the warning on close when having multiple tabs while opening tabs from last session. I can deal with it. Lol.

Just hopefully in a future release this clash will be fixed. I'm probably going to downgrade to another version of firefox that was suggested to me since I'm also having issues with shockwave flash causing firefox to hang und ultimately needs to be force closed otherwise having to have flash disabled to use firefox.

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I think what is seen could well be the expected; or at least the accepted; behaviour. Here are my personal thoughts on this issue.

I note you close down with red x i.e. you are closing down the window rather than exiting Firefox as intended by using the Firefox menu option. It is probably best to shut down Firefox properly.

If I have one instance of Firefox with two Firefox windows open, having multiple tabs open in each. I get a warning if I use the close down window option. That makes sense because the window may have more tabs on it than are displayed. There is a danger I could lose those many tabs when I eventually close down Firefox.
When I close the final window there is no warning.

  • I have no need for a warning on closing down Firefox, it is set to restore those tabs on restarting.
  • Alternatively If I set Firefox to open with Homepage tabs I get the warning about closing multiple tabs.

At one time IIRC we had to specifically opt to save tabs on closing down, this is no longer the case Firefox does this unprompted by default.

I see you say you want this

Und again, I need/want both of them. More so the tabs from the last session, but I really really really really really want the warning.

I have difficulty understanding any necessity for this however.

It is sometimes possible to get changes and improvements made to Firefox, but they usually need some good work-case explained that shows the benefits and advantages of the proposed change.

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You mention a second subject.

I'm probably going to downgrade to another version of firefox that was suggested to me since I'm also having issues with shockwave flash causing firefox to hang und ultimately needs to be force closed otherwise having to have flash disabled to use firefox. 

Downgrading Firefox
Flash is notorious for causing Firefox problems. I suggest you start a new thread about that. If at all possible you should try to avoid downgrading to an unsecure & unsupported version of Firefox. it will increase risks to your system and Personal data. (There are methods of mitigating the risks, using a virtual machine or operating within a secure intranet for instance)

Try Flash with Protected Mode Off
Worth a try as it takes minimal effort & often solves Flash Problems whilst allowing current and more secure FlashPlayer to be used. See

If you wish to pursue these subjects further I note you have already started a thread you may as well continue the discussion in that thread, but also post back here so we can follow both.

  • Firefox is having "Script" issues (Not Responding) und possibly Flash issues? /questions/978181
    • try ensuring you close down Firefox using the menu, that may even help with Flash problems.

Your experience in submitting troubleshooting information on the forum
(This is out of curiosity, but with the intention of pressing for changes if forum faults are discovered.)

There are yet more changes to this forum underway. Mozilla recently tried to improve the experience for first time users of the forum and a troubleshooting app option was included in the workflow to try to encourage users to submit full troubleshooting information.

I would be interested to know what you thought

I sometimes wonder if users are not trying to use that, or whether forum users run into problems in using it. At one point I wondered whether there was a problem if too much data was included but never actually proved that conjecture.

Assuming you are using the forum, and not merely replying by email look towards the top in the right hand margin for clickable buttons

  • Question Details -V- More System Details -> [Additional System Details]

You will note that includes only partial information. There are no changed prefs or extensions listed. Compare for instance the information in this thread /questions/978130 with full information.

I believe your mystery plugins are Windows related

  • NPWLPG relates usually to Windows Live Photo Gallery
  • 5.1.20913.0 will be Silverlight
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Yes, I figured out those extensions und as well as even when closing down firefox via the menu exit, same issues still occur.

As I stated, I've pretty much given up on the warning on close whilst using the remember tabs from last time.

I'm on a newer version of Firefox, 26.x.

It still has the warning issue as in this original post und then the flash issue as well. But, my work around is okay for now.

As you stated, Firefox has a history of issues with flash, und I've exhausted about everything from the help that I've received on both issues. Some have been able to reproduce, some haven't.

I've found a way around flash, so unless there's some miracle cure Adobe/Shockwave und Firefox come up with, I'm pretty much done with the issues since the work around.

I did try that protected mode off feature, und it sort of worked, sort of not.

I can shut my computer off, turn it back und open Firefox up und go to a webpage that has flash.

That's a plus, however, the negative side is that even though it will open a webpage with flash, it first causes Firefox to freeze (the more the flash content, the longer the freeze). But, it will eventually load the page. It took Adobe's test flash page about 4 minutes to load. Und that's without it showing the flash box for testing. Timing on when it pops up, if it pops up, is unknown.

Tried my workaround, however it still gave me issue. Both with und without restarting. I went back in und changed the mms.cfg file to what it was originally, putting the protection back on, I guess.

Then, I did my workaround after changing the file, und it's working perfectly. At least until I shut my comp down once I hop off here.

Even if I exit out of Firefox, both “x” und menu exit, it will repeat this issue until I reinstall flash, as I mentioned in my other forum post.

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Thanks for posting back. I will tag your other post for escalation and see if anyone else is able to help you.

Maybe you should mention whether the problem occurs on all Flash content sites. If it is a single site maybe the problem is with the site or the FlashCookies.

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Thank you for the details on your workaround and the discussion on this. It will really help us to see what you are seeing with the Flash issue. There was a silent update for Adobe Flash from 11.9.900.152 from .117 on November 25, between the time you used it the first time.

There is a bug filed for this issue [Bug 937933]

In the meantime it is possible to go into the plug in preferences and have is ask to be activated.

For hanging, if it is particular sites, that info would be great for the bug :-)

Modified by guigs

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You're welcome. Und ask to activate for flash doesn't matter.

As I stated on my other thread regarding the issue, it doesn't matter what website it is, if it has flash it will cause firefox to hang. I've even tried websites that friends use that I've never used that have flash, und when I go to them, they hang und screw up firefox.

It's not some websites, it's all websites with flash that cause my firefox to trip up.

But, with my work-around, it makes the flash issue disappear. After I do my work-around, all websites containing flash run perfectly.

Even when I have it set to "ask to activate", sure, none of the flash shows, but as soon as I click "allow this time", BAM - freeze/hang/crash/restart mandatory. Und that's before I install flash before I hop on firefox.

So, it's an issue with flash period, not periodically or depending what website.

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Hi, There was an issue with Youtube that sent an update to a plug in Hola [Bug 941892]

Bug 941892 Hola latest version solved this crash. The version was submitted last week  ..." [#c18] 

edit the link is broken. Comment proper fix is in Firefox 28 ~J99

If the crashing persists, please let us know.

Modified by guigs

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P5yx0Z0,

Sorry I am losing track of these two threads

  • Important question:
    Is Flash player working to your satisfaction at present ?
  • Of little importance; if it is working; but if you wish to clarify
  • You initially started discussing this in the other thread
    Firefox is having "Script" issues (Not Responding) und possibly Flash issues? /questions/978181
  • If I understand that your work around is to reinstall Flash Player every day ! Is that correct ?
    If so that can not be a good solution
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John99,

It's fine. No, I do not have Hola installed. Und yes, my flash is now working perfectly. However, I still do not know the root cause of what the flash issue was. How it became "fixed" is I had a friend completely wipe my computer und install Windows 7 Professional. Since, I have not experienced any issue with flash regarding firefox.

No, I did not submit crash reports. I don't/didn't know I could after the fact (awkward). Not sure how to submit them, either.

Und yes, that is correct. Before my wipe und reinstall of my OS, I had to reinstall flash -everyday-. Not just everyday, sometimes twice a day. I had to reinstall flash on boot up. Every time I shut down my comp, something went funkified und on boot up, firefox wouldn't handle flash. I'd have to reinstall it before I could use Firefox.

But, flash is no longer an issue for me, however, not sure what the cause was prior to wipe, as aforementioned.

However, even with my wipe und install of Windows 7 Professional (upgrade from home premium), the initial issue of this thread is still an issue.

I'm unable to have both "show tabs from last time" und "warn when closing multiple tabs" functioning at the same time. I've pretty much given up on this issue, however. As I prefer my tabs being restored in comparison to warning on close. I guess I got better coordinated when I had to use Google Chrome for so long since they didn't have that function (at least that I know of). Lol.

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Thanks for posting back.

Glad you solved the Flash issue. Rather a drastic step having to reinstall the Windows 7 OS.

I have no more ideas on the closing tabs issues, and will have to leave it to rmcguigan or others to assist you with that issue.