I belief that the Roboserver is down: 

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Servlet execution threw an exception

root cause

java.lang.OutOfMemoryError: Java heap space

note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.

Apache Tomcat/5.5.17