MFPLI00123S Addition of locators (POINTERs and/or OFFSETs) is invalid.

Under normal circumstances it does not make sense to add LOCATORs.
Resolution:
Under unusal circumstances addition of pointers x and y can be obtained by PTRVALUE ( BINVALUE (x) + BINVALUE (y)). Likewise by using OFFSETVALUE ( BINVALUE (x) + BINVALUE (y)) when x and y are offsets.
Module:
PLSP2.TB