Sense code 10145046 received with session activation failure

Problem statement: Session activation failed with the AS/400® sense code 10145046.
Common symptoms: An attempt was made to establish a session from one AS/400 to another AS/400 across a VTAM® network. The session failed to complete, and route selection errors occurred on the initiating AS/400.
Probable cause: The AS/400 (NETC) is sending VTAM (NETA) a CDINIT that specifies a session in a third network that is not supported in this release of VTAM. VTAM rejects the session, and the AS/400 returns the sense code 10145046 to VTAM.
User response: Verify that APPN sessions across three networks are not present in your system. Sessions across three networks using APPN links are not supported by VTAM unless you have specified BN=YES to enable the VTAM border node function.