Answer
This is caused by the Integration Server getting stuck endlessly retrying processing of a reference to a non-existent Application Message. Regardless of whether a specific patch for the underlying bug has been applied yet, a reliable self-service workaround is to stop the Integration Server and clear its persistent store by deleting the .dat files under wls_domain\<InstanceID>\servers\IntServer2\data\store\diagnostics and wls_domain\<InstanceID>\servers\IntServer2\data\store\default, then restart the Integration Server — this clears the stuck message references causing the endless retry loop and stops the flood of repeating error rows.