That's something on the browser OS side.   What browser are you using?  The Webpage sees that it's a java applet and calls Java Runtime on the host.  I would clear my browser and java cache and try again. 
Oracle is dropping support for Java 6. How do I get Grp Mgr to work with java 7? I have a PS 5000 at fw version 6.02.  Thanks.
Using EQ Group Manager with Java 7