Hello Pascal, I had the ecs-1.4.2.jar file in ecs/ecs/1.4.2 and also these 2 files - ecs-1.4.2.pom, ecs-1.4.2.pom.sha1. But I deleted that entire folder and ran maven again. It worked. :-) Thanks.... Can you tell me what does "xwiki-core-1.2-rc-1.jar" contain and how is it different from "xwiki-core-1.3-SNAPSHOT.jar" Both these jars are present in the "\XWiki Enterprise\webapps\xwiki\WEB-INF\lib" If I replace both of these with the "xwiki-core-1.4-SNAPSHOT.jar" that was created as a result of the build, I get ClassDef not found error for the org.observation.event class But, it works if I just replace the 1.3 snapshot with 1.4 snapshot. Is that how it is supposed to behave. what is "xwiki-core-1.2-rc-1.jar" for? Thanks _______________________________________________ devs mailing list devs(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/devs