EJBClient message "Unsupported message received with header 0xffffffff" generated when reconnecting to a non-clustered server ----------------------------------------------------------------------------------------------------------------------------- Key: WFLY-4273 URL: https://issues.jboss.org/browse/WFLY-4273 Project: WildFly Issue Type: Bug Components: EJB Affects Versions: 8.0.0.Final Reporter: Richard Achmatowicz Assignee: Richard Achmatowicz Fix For: 9.0.0.Beta1 The EJBClient protocol handler on the server side, org.jboss.as.ejb3.remote.protocol.versionone.VersionOneProtocolChannelReceiver, will send out a full cluster topology report to a connecting EJBClient. This will happen in particular when the client reconnects after a server which was initially up went down and came up again. If the server is not clustered, the report gets sent out anyway, and erroneously with an empty message body. This message gets processed on the client side by org.jboss.ejb.client.remoting.ChannelAssociation.processResponse() which cannot recognize the message header. The exception results. One way to fix this is to only send out the cluster topology message if the node is actually clustered.