Ok, I did now following: I openend the file com.springsource.com.sun.tools.xjc-2.1.7.jar and edited the file META-INF/MANIFEST.MF In lines 267 and 268 I removed following string: /,org.relaxng.datatype;version="2.1.7",org.relaxn g.datatype.helpers;version="2.1.7";uses:="org.relaxng.datatype"/ I saved it and it started working. I opened following bugreport: https://issuetracker.springsource.com/browse/EBR-817 https://issuetracker.springsource.com/browse/EBR-817 Please tell me, if this resolves your problem? /Kind regards Christian -- View this message in context: http://drools.46999.n3.nabble.com/Drools-5-3-0-on-Felix-OSGi-tp3769538p37... Sent from the Drools: User forum mailing list archive at Nabble.com.