Whenever I open up the page http://www.runescape.com/game.ws? in google chrome I get the notice, "IcedTea was blocked because it is out of date" and gives me the two options of updating it or running this time.

I've gone to the link attached to the option of updating it and its a wikipedia page http://icedtea.classpath.org/wiki/Main_Page that wasn't helpful for me because I didn't know what to download and install.

Whenever I click, 'Run this time' it works momentarily but it is prone to have the runescape interface in the browser disappear and be replaced with a black screen.