Your contribution is very helphul. I'm going to install Drools 5.3.0. I hope it will work well. Thanks very much -- View this message in context: http://drools.46999.n3.nabble.com/Error-with-Helloworld-Drools-projet-tp3985433p3985595.html Sent from the Drools: User forum mailing list archive at Nabble.com.