i was having the same problem using ubuntu 12.04 and ireport 3.7.6, ireport 4.6.0 and 5.0.1. I finally solve the problem by forcing java version to be OpenJDK 7. I Changed the default Java, and javac version used on Ubuntu by doing: java : sudo /usr/sbin/update-alternatives --config java java compiler : sudo /usr/sbin/update-alternatives --config javac java web start : sudo /usr/sbin/update-alternatives --config javaws
