How to disable Firefox blocking of old Java

ok, before we go any further here. I am TOTALLY against this.  I would like to have our workstations on the latest version of Java, BUT, it isn't my call.  
Anyway, Can anyone tell me how I can get Firefox, Specifically version 37.0.1 to allow older versions of java?

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Answers (2)

Posted by: dunnpy 9 years ago
Red Belt
You didn't mention what you've already tried - if you detail what you've attempted before posting in your question you might get more of a revelant response.

I've downloaded FF 37.0.1 and Java 1.6.39 and tested in an offline enviroment and I can get the plugin enabled.

If you launch your browser and enter 'about:config' in the address bar, you can gain access to the raw configuration settings.

Look for 'extensions.blocklist.enabled' and set it to false.
This will remove the 'is known to be vulnerable message and enable the previously greyed out 'ask to activate' & 'Always active' options.

You can then set the plug in to always enable by setting the relevant value for 'plugin.state.<plugin_name>:

0 - Never Active
1 - Ask to Active
2 - Always Active

I saw 'plugin.state.java' & 'plugin.state.ndeployjava' when looking during my testing.

These settings are stored in the '%appdata%\Mozilla\Firefox\Profiles\<random_name>\prefs.js' file.

If you try this, and it meets your requirements - then you should be able to incoroprate that into a package using the default configuration file for Firefox (loads of posts on ITNinja and other fora for that).

Hope that helps,

  • Thank you very much Dunnpy!
    I have tried what you've advised, & it has worked well for me.
    I was looking for this solution for a long time.
    :) - MikeQuest3 4 years ago
Posted by: dunnpy 9 years ago
Red Belt
You may get somewhere if you disable the block list function in the FF preferences - this might point you in the right direction.


  • Yea tried that first, No luck. - usgrcm 9 years ago
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