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I have found a fix for "Firefox is not responding" freezes when using Adobe flash.

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Windows 7 Home Premium, SP1. Firefox began freezing "Firefox is not responding" while watching videos using flash, immediately after FF Release 40 installed. I tried all the "fixes", FF safe mode, Flash in unprotected mode, refresh FF (and rebuild tool bar, and get back classic theme), hardware acceleration, etc. I did not have any problems using IE with Flash (Active X) on the same videos. FF support told me the problem was having two Flash Players, and to uninstall both, using Adobe's uninstall tool. Since videos on my laptop are my only form of entertainment, I was reluctant to uninstall Flash for IE, when it was working Fine. My solution was to stop using FF for videos, and use IE. With FF release 41, FF began freezing on all websites using any flash content. I really like FF, and it is my preferred browser, but it became totally unusable.

As a last gasp try to fix the constant "Firefox is not responding" problem, I set FF to not update automatically (check for updates,but let me choose whether to install), and I installed FF 38.0.5. I know that someone will comment that doing this is not advised, and that it will leave me vulnerable to attack. I have since watched about 30 hours of video without a single "Firefox is not responding", or a flash crash. I use Norton as anti virus, so I'm not sure how protected I am, but I am happy to be able to use FF again. The "About Firefox" page in help shows me on 38.0.5, and has a button to allow update to the current release, so I am confident going back to the current release would be easy.

I have to wonder what in FF 40 and 41 was causing the problem? I think that problems actually started with FF 39 with Flash crashing constantly, and changed to FF freezing with release 40. Here is a link to my earlier post about the freezing https://support.mozilla.org/en-US/questions/1079195#answer-770460

I may have unique variables, Windows 7, FF and Flash, Comcast Internet, Xfinity online, but with the freezing occurring on any website using flash content, and the problems going away after down grading to FF 38, I have to think the problem is within FF ?

Thanks, and it is so nice to be able to use FF again!

Windows 7 Home Premium, SP1. Firefox began freezing "Firefox is not responding" while watching videos using flash, immediately after FF Release 40 installed. I tried all the "fixes", FF safe mode, Flash in unprotected mode, refresh FF (and rebuild tool bar, and get back classic theme), hardware acceleration, etc. I did not have any problems using IE with Flash (Active X) on the same videos. FF support told me the problem was having two Flash Players, and to uninstall both, using Adobe's uninstall tool. Since videos on my laptop are my only form of entertainment, I was reluctant to uninstall Flash for IE, when it was working Fine. My solution was to stop using FF for videos, and use IE. With FF release 41, FF began freezing on all websites using any flash content. I really like FF, and it is my preferred browser, but it became totally unusable. As a last gasp try to fix the constant "Firefox is not responding" problem, I set FF to not update automatically (check for updates,but let me choose whether to install), and I installed FF 38.0.5. I know that someone will comment that doing this is not advised, and that it will leave me vulnerable to attack. I have since watched about 30 hours of video without a single "Firefox is not responding", or a flash crash. I use Norton as anti virus, so I'm not sure how protected I am, but I am happy to be able to use FF again. The "About Firefox" page in help shows me on 38.0.5, and has a button to allow update to the current release, so I am confident going back to the current release would be easy. I have to wonder what in FF 40 and 41 was causing the problem? I think that problems actually started with FF 39 with Flash crashing constantly, and changed to FF freezing with release 40. Here is a link to my earlier post about the freezing https://support.mozilla.org/en-US/questions/1079195#answer-770460 I may have unique variables, Windows 7, FF and Flash, Comcast Internet, Xfinity online, but with the freezing occurring on any website using flash content, and the problems going away after down grading to FF 38, I have to think the problem is within FF ? Thanks, and it is so nice to be able to use FF again!

Chosen solution

Of course I'm going to say that Firefox 38.0.5 has serious drawbacks in the security area! When Firefox 39, 40, and 41 were released, Mozilla disclosed several security flaws that were fixed in those later versions.

If you want to stick with Firefox 38 until the Flash problems shake out, maybe you'd like to try out a different variant of Firefox called the Extended Support Release (ESR). This is designed for companies that require a longer cycle time between feature changes, and currently is based on Firefox 38. It will get security updates over the next several months, but not get new features, so non-security-related changes to plugins will not kick in for quite a while.

If you decide to try it, here is how I suggest installing it:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 38.3.0esr from https://www.mozilla.org/firefox/organizations/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the existing Firefox program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\Fx3805

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\Fx3805

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Success?

Note: Some plugins may exist only in that old folder. If something essential is missing, look in these folders:

  • \Fx3805\Plugins
  • \Fx3805\browser\plugins
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All Replies (8)

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Chosen Solution

Of course I'm going to say that Firefox 38.0.5 has serious drawbacks in the security area! When Firefox 39, 40, and 41 were released, Mozilla disclosed several security flaws that were fixed in those later versions.

If you want to stick with Firefox 38 until the Flash problems shake out, maybe you'd like to try out a different variant of Firefox called the Extended Support Release (ESR). This is designed for companies that require a longer cycle time between feature changes, and currently is based on Firefox 38. It will get security updates over the next several months, but not get new features, so non-security-related changes to plugins will not kick in for quite a while.

If you decide to try it, here is how I suggest installing it:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 38.3.0esr from https://www.mozilla.org/firefox/organizations/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the existing Firefox program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\Fx3805

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\Fx3805

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Success?

Note: Some plugins may exist only in that old folder. If something essential is missing, look in these folders:

  • \Fx3805\Plugins
  • \Fx3805\browser\plugins
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Thanks, jscher2000.

I'm not a super user, so I need more information.

How exactly do I edit the program file names (please be detailed. Assume I am an OS idiot).

If I decide to go back to my 38.0.5, how do I remove the ESR version? Uninstall from control panel, and then rename the old files?

Thanks for a constructive solution. I'm frazzled from working all the other suggestions that didn't work, so it may be a few days before I'm willing to start experimenting again. If I can make these changes, I will post my results, in case anyone else can use the info.

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Hi kuzink, to rename a folder, you can use Windows Explorer (hold down the Windows key and tap E to launch it).

Usually the left column will show your computer and under that the C drive. Double-click the C drive, then on the right side double-click Program Files (x86). Scroll down to Mozilla Firefox, right-click it, and choose Rename. This should make the name editable and you can type Fx3805 and press Enter (or click away from the edit) to finish.

If you decide to go back, you can repeat the Clean Reinstall process, but name the new Mozilla Firefox folder to something like FxESR so you know what it is.

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Thanks jscher2000! I can follow that. I'll try tomorrow and post results. Edited 9/30/15 10:25pm MDT Jscher2000, if you see this, thank you!

Install of ESR was quick and easy. I was surprised that I was prompted to restore my last session, and I was able to. All browser history, bookmarks, classic theme restorer intact. Had to check "About Firefox", to verify ESR. Amazing. "Firefox ESR 38.3.0 You are currently on the esr update channel"

Only lost 2 buttons from tool bar: Pocket and Calling and Conversation. Found Calling... in menu/customize/additional toolbars/advanced. Found online source to download Pocket addon. I don't use either, so no problem.

Thanks again!

Modified by kuzink

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Separate Issue: Update your Flash Player Version 19.0.0.185
https://www.adobe.com/products/flashplayer/distribution3.html
Note: Windows users must download the “Internet Explorer” and “Plugin-based browsers” installers.

Note: Edge on Win10 does not use ActiveX version but its own Flash.

See if there are updates for your graphics drivers https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

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FredMcD, thanks.

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Jscher2000, if you see this, thank you! Install of ESR was quick and easy. I was surprised that I was prompted to restore my last session, and I was able to. All browser history, bookmarks, classic theme restorer intact. Had to check "About Firefox", to verify ESR. Amazing. "Firefox ESR 38.3.0 You are currently on the esr update channel"

Only lost 2 buttons from tool bar: Pocket and Calling and Conversation. Found Calling... in menu/customize/additional toolbars/advanced. Found online source to download Pocket addon. I don't use either, so no problem.

Thanks again!

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Hi kuzink, thank you for pointing out those missing features. I wasn't aware of that.