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In Firefox 17 on Ubuntu 12.04 (Precise Pangolin), I cannot get the Java verification applet to work (needless to say, I cannot get any Java applications on the browser working).

I already tried uninstalling and re-installing the AFAIK necessary components (screenshot 1, screenshot 2) (before, I had Java 6 AND 7 installed. I already tried leaving only Java 7, and now I am back to leaving only Java 6), but I cannot get it to work.

How do I get JRE up and running in Firefox?

UPDATE: I had so much trouble with Java in Firefox quitting working after upgrades, etc. that I gave up on Firefox entirely (my main purpose of using this Ubuntu machine is to safely run Java applications away from my main computer). I now run Opera and never had any problems again - it comes with Java, and it just works.

share|improve this question
Are you certain that no applets work? I can't get the verification applet to run but I can get other applets to work, such as the ShapeMover example in the Java Tutorial. – iBelieve Nov 29 '12 at 16:01
All I ran was sudo apt-get install icedtea-plugin and all applets that I've tried have worked except the verification applet you mentioned. – iBelieve Nov 29 '12 at 16:05
I don't know if it makes a difference, but I'm running Ubuntu 12.10. – iBelieve Nov 29 '12 at 16:11
Spencer, I dont know when it started working, but the applet I needed to run is working, eventhough the test applet does not. Since I was checking to see if it was working using the damn test applet, I was still under the impression it wasn't working. It must have gotten fixed during my uninstall-reinstall ordeal. Thank you. Feel free to submit an answer. – Gaia Nov 29 '12 at 21:21
up vote 6 down vote accepted

It appears that the Java verification applet doesn't work with the implementation of Java that Ubuntu uses (OpenJDK), but other applets should work if you install the Java web plugin, which is a plugin that lets Java applets run in a web browser.

According to the community documentation for Java,

Browser plugin

  1. Install the icedtea6-plugin package using any installation method.
  2. Install the icedtea-7-plugin package using any installation method.

If you are using or want to use the default version of Java included with Ubuntu, just run

sudo apt-get install icedtea-plugin

If you want to use a specific version, just use the packages listed above.

share|improve this answer… – Gaia Nov 30 '12 at 9:29
I have icedtea installed already and applets are not loading for me unfortunately – anon58192932 Aug 19 '14 at 21:36

You need the browser plugin for Java to work in Firefox.

sudo apt-get install icedtea-plugin

Then sudo update-alternatives --config java

Check which version is activated: java -version

Install the icedtea-web plugin if not yet installed: sudo apt-get install icedtea-web

share|improve this answer
I already had it, but naturally you weren't aware of that because I was editing the answer to include info on what I already had installed (which took me a while, because I cannot post images/more than 2 hyperlinks/etc). I wish SE checked your network reputation and instantly gave old members with more than X points on a network site 10, instead of 1 point, to start. But that's a suggestion for Meta. – Gaia Nov 29 '12 at 13:36
See this answer: – To Do Nov 29 '12 at 13:42
i reinstalled openJDK7, and now I have both installed, like I did before. I restarted firefox but no go on the verification applet. – Gaia Nov 29 '12 at 14:41
Thank you, see comment… above – Gaia Nov 29 '12 at 21:21

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