PH_CON - Time Ticket Confirmation for Phase Process instruction category error message

dear experts ,

i am using PH_CON - Time Ticket Confirmation for Phase Process instruction category in my process order , PI_PHCON is the process message category assigned to it . i.e. i am using standard SAP PIC and PMC .

while creating control recipe in process order the , it giving error log and not creating the CR .

"Value cannot be assigned autom. to char. 0520 PPPI_UNIT_OF_MEASURE in

proc.instr. 0000 phase 0020 "

i.e its expecting some value for the UOM characteristics. when i manually give some value or manually do auto assign values in process order i am able to create the control recipe .

0500 PPPI_INPUT_REQUEST                                                                  Yield to confirm:

0510 PPPI_REQUESTED_VALUE PPPI_YIELD_TO_CONFIRM

0520 PPPI_UNIT_OF_MEASURE

please guide , if any one has faced similar issue before.

regards,

satish