A couple of things. One, the URLs no longer have "/rumble/" like the used to. Removing that fixed the URLs. Also, it appears the accepted clients are now 22.214.171.124 and 126.96.36.199. It appears the 1.7.3.x clients are no longer accepted. I'll have to check, but the 1.8 Robocode clients may require Java 1.7. Guess I'll find out in the next few days. I'll try to update this page, but I am kind of learning as I go to figure it all out.