For this function to be available, VLF must be active and the active COFVLFxx member of SYS1.PARMLIB must include statements defining the IRRSMAP VLF class. Update the COFVLFxx member of SYS1.PARMLIB as follows:

CLASS NAME(IRRSMAP)        /* SMAP table for z/OS UNIX System Services   */
EMAJ(SMAP)                 /* Major name = SMAP                          */