Update BI-Publisher from 11.1.1.5 to 11.1.1.6.9 fails: he target EJB for the ejb-ref could not be found

After updating Weblogic Server 10.3.5 and BI-Publisher 11.1.1.5(the whole BI suite) to Weblogic Server 10.3.6 an BI-Publisher 11.1.1.6.9 I got the following errors in managed server log:

<Jul 30, 2013 1:18:41 PM CEST> <Error> <Deployer> <BEA-149231> <Unable to set the activation state to true for the application 'bipublisher [Version=11.1.1]'.weblogic.application.ModuleException: Could not setup environmentat weblogic.servlet.internal.WebAppModule.activateContexts(WebAppModule.java:1505)at weblogic.servlet.internal.WebAppModule.activate(WebAppModule.java:440)at weblogic.application.internal.flow.ModuleStateDriver$2.next(ModuleStateDriver.java:375)      at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:52)      at weblogic.application.internal.flow.ModuleStateDriver.activate(ModuleStateDriver.java:95)      Truncated. see log file for complete stacktraceCaused By: weblogic.deployment.EnvironmentException: [J2EE:160101]Error: The ejb-link 'MetadataServiceBean' declared in the ejb-ref or ejb-local-ref 'ess/metadata' in the application module 'xmlpserver.war' could not be resolved. The target EJB for the ejb-ref could not be found. Please ensure the link is correct.      at weblogic.deployment.BaseEnvironmentBuilder.addEJBLinkRef(BaseEnvironmentBuilder.java:469)      at weblogic.deployment.EnvironmentBuilder.addEJBReferences(EnvironmentBuilder.java:496)      at weblogic.servlet.internal.CompEnv.activate(CompEnv.java:157)      at weblogic.servlet.internal.WebAppServletContext.activate(WebAppServletContext.java:3145)      at weblogic.servlet.internal.WebAppModule.activateContexts(WebAppModule.java:1503)      Truncated. see log file for complete stacktrace

After "updating" and restarting the application via weblogic console, the error was gone and BI-Publisher runs fine.