This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Plugins won't disable (or if disabled, re-enable.)

  • 7 replies
  • 13 have this problem
  • 10 views
  • Last reply by philipp

more options

While trying to track down which Add-On is hammering my CPU, I found another odd behaviour while trying to disable plug-ins one-by-one: With certain plug-ins (specifically Flash, Foxit Reader, and Silverlight), the next time I restart Firefox, they are enabled again. After disabling them a few times, they finally stay disabled on restart, but then I can't re-enable them. (Same thing happens, but in reverse; I enable them, but they return to disabled on restart.)

At one point I was trying to disable Foxit and Silverlight and re-enable Flash. Each time I restarted, Foxit and Silverlight would be enabled again and Flash disabled again. After about five or six attempts over two days, suddenly it worked.

Has anyone else noticed this behaviour? I don't recall ever having problems disabling unwanted plugins before.

Note: This is about plug-ins, not extensions. And this isn't about permanently disabling or removing plugins.

While trying to track down which Add-On is hammering my CPU, I found another odd behaviour while trying to disable plug-ins one-by-one: With certain plug-ins (specifically Flash, Foxit Reader, and Silverlight), the next time I restart Firefox, they are enabled again. After disabling them a few times, they finally stay disabled on restart, but then I can't re-enable them. (Same thing happens, but in reverse; I enable them, but they return to disabled on restart.) At one point I was trying to disable Foxit and Silverlight and re-enable Flash. Each time I restarted, Foxit and Silverlight would be enabled again and Flash disabled again. After about five or six attempts over two days, suddenly it worked. Has anyone else noticed this behaviour? I don't recall ever having problems disabling unwanted plugins before. Note: This is about plug-ins, not extensions. And this isn't about permanently disabling or removing plugins.

Chosen solution

hello, the problem that you're seeing may be bug #839728 which will be fixed in an upcoming firefox release. as a workaround in the meantime you could try to close all other tabs before you're changing the state of plugins in the addon manager (a restart might be necessary because plugins running in the background take a certain time before they get terminated).

Read this answer in context 👍 2

All Replies (7)

more options

This sounds like a problem with the pluginreg.dat file.

You may have security software preventing Firefox from changing the file.

You can delete the pluginreg.dat file in the Firefox Profile Folder and maybe addons.sqlite as well to reset the plugin registry databases and re-enable all plugins.

You can use this button to go to the Firefox profile folder:

Modified by cor-el

more options

Chosen Solution

hello, the problem that you're seeing may be bug #839728 which will be fixed in an upcoming firefox release. as a workaround in the meantime you could try to close all other tabs before you're changing the state of plugins in the addon manager (a restart might be necessary because plugins running in the background take a certain time before they get terminated).

more options

Madperson,
That's sound like the one. Thanks for the info (and the effort).

Not solved, but it's always reassuring to know a) it's not something I did, and b) others are taking it seriously.

Modified by Paul451

more options

I recently ran into this issue as well when trying to enable plugins after disabling them temporarily. I discovered a work around that worked for me. After clicking "enable" I clicked on "more" which sends you to screen about the plugin. Then I clicked on "plugins" on the left to return to plugin menu and it was enabled. If I tried anything else the plugin was not enabled. Hope this helps someone.

more options

this will be fixed in firefox 22.

more options

It looks like only one plugin can be disabled or enabled at a time. If you try to enable or disable multiple plugins, only the first one from the top of the list is enabled or disabled.

Example: plugins A, B, and C are all enabled. Disabling B and C, closing the Add-ons Manager tab, then re-launching Add-ons from Tools reveals that only plugin B was disabled.

Then, disabling A and B, closing the Add-ons Manager tab, and re-launching Add-ons from Tools reveals that only plugin A was disabled.

Hope this helps!

more options

if you're affected by the issue you can try firefox 22 beta which is now available at mozilla.org/beta.