I was able to start the arena last week. I had jdk version 7 in my system. Yesterday, I installed oracle java version 8 to install Android Studio. From then on, I am unable to launch topcoder arena. Is it due to the oracle java? Please help me..

2 Answers 2


For TopCoder (and this may work for other sites too), for the current version of Java from Oracle (Java 8 update 91 while posting), you may NOT be able to launch the arena by simply running the command javaws ContestAppletProd.jnlp because of some newly added security restrictions in Java. In order to be able to launch TopCoder arena, I had to perform the following -

  1. Open Java Control Panel by running command javaws -viewer on terminal.
  2. On the Security tab, set the desired security level to High to have somewhat permissive behavior.
  3. Add TopCoder to the Exception Site List in the same tab. For me, adding the TopCoder URL alone didn't suffice. I had to add the HTTP URL (http://www.topcoder.com) to the list as well to be able to launch the arena.
  4. Apply these changes to Java Control Panel and relaunch the arena by running the command javaws ContestAppletProd.jnlp.

Hope this helps!


Try doing this in the directory where the applet is stored-

javaws <name_of_applet>
  • U mean javaws Topcoder? I wrote it and I got "unable to launch application error" Jan 28, 2016 at 17:18
  • No, I mean the filename of the applet. It is generally ContestAppletProd.jnlp . Did you type it into the terminal after cd -ing into the folder?
    – goelakash
    Jan 28, 2016 at 17:19

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