Like others I am attempting to run this on Mountain Lion and receiving this error:
http://d.pr/i/ryYHere's how I'm starting the client: $ sudo javaws ~/Downloads/updater.jnlp -verbose
I'm sure it has something to do with my system, but I'm not sure how to address it. The reason I'm starting it from command line is because when I try and start it by double-clicking it in finder it tails me that I must install Java Web Start. However, as you can see from the fact that I'm getting to the error, I already have it installed.