“Java Web Start not found” using java 1.6

Question

I'm running Mac OS 10.7, and I have the latest version of java installed. Nonetheless, when I try to launch the TopCoder competition arena, I see this error:

Answer 1

Did you try clicking on the button? Viewing the page content, I see that this button just downloads a JNLP file, which just works for me.

The site is trying to detect if something handles 'application/x-java-jnlp-file', but no plugin is registered to handle it. If you have Java installed it should register a MIME type handler for JNLP files, so it sounds like a bug. File one with Oracle.