Deploying Magnolia with JBPM 6 affects deployment feature of Weblogic/Websphere AS. It does't care if Administration Console, weblogic.Deployer, wldeploy Ant task or auto deploy directory is used all are affected.

Symptoms:
Magnolia can't be deployed to Weblogic. "weblogic.application.ModuleException: java.lang.ClassNotFoundException: org.jbpm.services.task.lifecycle.listeners.TaskLifeCycleEventListener". Full stacktrace http://pastebin.com/gsUy28DU

TaskLifeCycleEventListener is part of jbpm-human-task-core library. This library is excluded from the Workflow bundle. So if you remove exclusions from the workflow pom then "weblogic.application.ModuleException: java.lang.ClassNotFoundException: org.codehaus.janino.util.resource.ResourceFinder".

...

Workaround:
First deploy application which doesn't contain Magnolia Workflow with jbpm6 (etc. M5.2.2, M5.3 without workflow, etc.). And then in deployment target location replace deployed webapp by new webapp which contains workflow with jbpm6

Related forum post:
https://community.jboss.org/thread/237081