I'm getting error "javax.jcr.PathNotFoundException: Node not found /exo:services" when deploying Site Publisher.

Issue

• When we try to deploy the portal application which makes use of Site Publisher, the following error is encountered.

• I have a new JBoss EPP 5 instance. The server starts properly without raising any exception. Trying to deploy the file gatein-wcm-extension-<version>.ear, as instructed by the installation guide, raises the following exception:

  ERROR [org.exoplatform.services.deployment.ContentInitializerService] (main) An unexpected problem occurs when deploy contents
  javax.jcr.PathNotFoundException: Item not found /exo:services in workspace portal-system
      at org.exoplatform.services.jcr.impl.core.SessionImpl.getItem(SessionImpl.java:542)
      at org.exoplatform.services.jcr.impl.core.SessionImpl.getItem(SessionImpl.java:100)
      at org.exoplatform.services.deployment.ContentInitializerService.start(ContentInitializerService.java:64)
  ...
  ERROR [WCMContentInitializerService] Error when start WCMContentInitializerService: 
  javax.jcr.PathNotFoundException: Node not found /exo:services
       at org.exoplatform.services.jcr.impl.core.NodeImpl.getNode(NodeImpl.java:946)
       at org.exoplatform.services.deployment.WCMContentInitializerService.start(WCMContentInitializerService.java:81)