MFPLI00008S "label-prefix" is a subscripted label prefix but has previously been declared with a different data type or a different number of dimensions.

label-prefix has either been declared as something other than an array of LABEL variables or the subscript is not within the bounds of the array.
Resolution:
Correct the subscript or the array bounds.
Module:
PASS1.PL1, SUBLAB.PL1