PublicationContractManager::ProcessError/RetryResponse(): 'Unknown error occurred (possibly a Java HTTP exception). Check Application Server log for details. (94,56)'.

ISSUE:
Sending Asynchronous messages from peoplesoft to peoplesoft gives out the error message as “PublicationContractManager::ProcessError/RetryResponse(): ‘UserName not defined in database. (158,55)’.”
PRE CHECK:
1.Check whether the basic  setup of the Integration Broker is good(ie pinging the node and gateway URL to success).
2.Check whether all the corresponding queues, handlers and routings are active.
SOLUTION:
Goto Main Menu->PeopleTools–>Itegration Broker–>Configuration–>Service Configuration
Goto –> Exclude PSFT Auth Token tab–>search for the required service–> check the Exclude Token –>Click Save
This applies to the Peopletools 8.5x.The issue was not addressed in the lower peopletools version.