AFB

Explanation
While JES3 dynamic support program (DSP) for systems
network architecture (SNA) remote job processing (RJP) was executing
as a JES3 subtask or under an SRB, a JES3 module IATSNDA, IATSNDE,
IATSNDM, IATSNDR, IATSNDT, IATSNDU, or IATSNDV attempted to reuse
a still-active request parameter list (RPL).

System action
The system cancels the session associated with
the RPL and writes a dump. The system continues processing all other
sessions, including those associated with the same work station.

Programmer response
Analyze the dump to determine which RPL
is about to be overlaid and what data is about to be sent or received.

Source
JES3