Hi Kinney Associates,
Thank you for using the Support Forum. According to the current user documentation from February 21, 2019 : "XPAF supports the following versions of z/OS
Required changes when migrating to a new OS or JES version Have your systems programmer change the SMP/E JESMAC DDDEF entry for both the TARGET and DISTRIBUTION ZONES in the XPAF CSI to specify the new JES z/OS macro library.Rerun UMJOB101 before running XPAF on the new system. This will re-assemble your JES offsets table. "
If this does not help please consider contacting your support centre for further assistance.
What is the minimum level of XPAF that will run on z/OS 2.4?