Have you tired enabling that plugin?

Yes. I can't do it, because the "Enable" button is grayed out.

Sorry, I didn't realize that was on the blocklist.
https://bugzilla.mozilla.org/show_bug.cgi?id=430826#c59
There is a pref that can be changed in about:config to turn the blocklist off. You would also have to delete the existing blocklist.xml file in addition to turning off this preference.
extensions.blocklist.enabled

I stopped using QuickTime in 2004 or 2005 when I discovered QuickTimeAlternative - a lot slimmer installation and it doesn't "grab" all multi-media files type like QT seemed to do. I didn't have a problem with QuickTimeAlternative being blocked on Windows2000 up through last summer. That Bugzilla comment 59 mentioned that QTA 190 worked for him.
http://www.videohelp.com/tools/QuickTime_Alternative/old-versions#download

Good answer! I had to track down a back version of QuickTimeAlternative that would support Win 2000, but that was easy (filehippo.com). Embedded QuickTime content now works, and as a bonus, I have full support for those ogg formats in Wikipedia, that used to be such a hassle.

Finally, it's nice to know how to disable the block list, if I ever want to do that in the future. Many thanks!

You're welcome.

I have several extensions that are now "disabled for my protection"!

None are as ubiquitous as Quicktime, but it is still annoying. I really would like to simply UNINSTALL them now--but that button is also grayed out!

I changed the status of extensions.blocklist.enabled to FALSE, but I don't know where to find blocklist.xml.

Any help would be appreciated!!

Thanks--Diane

Diane,

Neither changing that pref to False or messing with the blocklist.xml file is going to help un-install those disabled extensions, all that night do is to allow those plugins to be enabled again. What you want to do is the opposite of what was being discussed in this thread - enabling plugins that were disabled by the blocklist file.

The first thing to do is to figure out which programs those plugins are associated with, and un-install those programs, if you don't want them to be used any longer. The actual "plugin" that Firefox uses is a very small part of the whole program. Beyond that you can delete the actual plugin files to get rid of them for just Firefox. I need to know which operating system you have before I can provide instructions for helping you identify where those plugins would be located on your hard drive for deletion.
For Mac OSX you will need someone elses help with that, I can't help you there. For Windows I can help you, and I might be able to help on Linux, too.

Thanks for the reply, I had had one persistent blocked extension that was a search optimizer of some sort and not associated with anything outside FireFox that I know of, but it's disappeared from the add-on list! Don't know how that happened, unless it was somehow associated with another add-on that I have uninstalled. I was tired of how slow browsing has been so I uninstalled a bunch of stuff that I only used once in a while.

I use WinXp and none of the blocked extensions appeared in my add/remove program control panel ap nor in the program files.

If you could tell me where FireFox stashes these add-ons for future ref, I'd be very happy!

Thanks again.

You should be very, very careful about simply unblocking plug-ins which are disabled for security reasons. There's more than enough evidence of a plug-in's dangers once it makes it to this point. The preferred solution is to update or remove the source of the plug-in.

That said....

If you can't find the source of a blocked add-in in the Add/Remove Programs control panel (APPWIZ.CPL), try running MSCONFIG and see if there's a startup item that looks like the same thing. Sometime startup apps can hide in HKLM\Software\Microsoft\Windows\CurrentVersion\Run (MSCONFIG will show you those). Some programs may have uninstalled in the past, but will leave behind startup services, plug-ins, or update utilities (Symantec, InstallShield are notorious for this).

More info on MSCONFIG and using it to troubleshoot issues can be found on Microsoft's online knowledge base.

You can also use http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx Autoruns

The goal was to reinstall mozilla shockwave video player or flash player as a plugin for my firefox. It was blocked when I tried to upgrade firefox. And, it did not firefox either since on Tiger the new 13 wont run. I had to downgrade firefox again and put back my plugins. What a pain. But, I did it successfully on my IMac at home in about 1 or 2 days of pondering the complexity. It was really easier than these suggestions. Simply go to edit about.config in your url box in the browser and agree. Then filter all those things so they find everything that starts with "extensions". Find the one like this: extensions. blocklist.url and it will say something about mozilla. You click it to edit and just remove all of that. There is no need to disable the entire block list. There is also no need to delete the entire file called blocklist.xml. That's easy to find because on IMac we just type if in the blue search magnifier at top right of screen. Then I just renamed it once I navigated to it using the finder. I renamed it because there was no reason to delete it when I can simply rename it and read it later. There might be something in there I want to keep, since this is just XML file it's possible to edit this myself manually once I figure out the patterns of the syntax. Or don't worry about that. But I noticed some things in there about java which I might allow to keep them once I figure out how to only remove the mozilla stuff from it. If I had an earlier version that would help me. I wonder if it removes those lines when I uninstall firefox again. But folks I am done it all works for me. My stuff is fast and not causing any problems like was reported as a risk to me. I did have to disable my norton firewall and virus checker while I reinstalled firefox and the shockwave flashplayer plugins from mozilla again, and a restart. And, I tested that in safari first which told me that firefox was the culprit and it was actually installed but would not show videos like in hulu using firefox, while in safari it worked. Hope it all makes send to you but to me it was just really one or two steps, which was enough to get it working, after a proper installation again of the right version expected to run videos in hulu and in other places like chat and youtube. Now I am good to go! I don't need to upgrade my Mac Tiger OS and I don't need new version of Firefox. I am ok as I am in my nice white IMac! And, mine runs fast and smooth. And, I got firewall to keep me safe with norton. I don't need the other stuff like new versions either. I am ok.