Did you do this?
[V9.2.0 Jul 2020]BACKMIG( backward-migration-target-vrm )
The queue manager is to start up and perform backward migration actions
such that it can be restarted at the backward-migration-target-vrm, and then
the queue manager is to shut down without ever being available to any
applications.
backward-migration-target-vrm
The version, release and modification number for the target version
for backward migration, for example 910. Backward migration to this release
must be allowed.
The release, if any, to which backward migration is allowed, is
indicated in the CSQY039I message at queue manager start up. If the CSQY039I
message is not emitted, backward migration is not supported to any release.
So +MQS1 START QMGR PARM(MQSIZPEM BACKMIG(910)
I am just guessing at the syntax, but something like that?
And your PARM member is correct?
If the CSQY039I message is not emitted, backward migration is not supported
to any release
Did you see any CSQY039I?
Lizette