This document describes the steps to resolve fatal error during execution of spoon script especially in Linux Servers. You might not face this issue if you are running spoon client.
Spoon script will look for xulrunner/Mozilla package in linux server under usr/lib directory to bootstrap x windows application but sometimes you may not know where exactly the xulrunner or mozilla package is installed in server. So you need to find it first using below command :
find / -name "mozilla" and then Set the variable value accordingly in script
Hope it helps this for those who launch Pentaho from server itself.