exit for validation of PO fields in ME21N / ME22N - After pressing check button

Hi,

I am looking to validate the standard fields partner- MF (MMPA-LIFNR) again of Purchase order items. So for this I used the customer exit EXIT_SAPMM06E_012 under the enhancement MM06E005 . it it working on Development client But not in Production. I am able to validate but it is triggering only when client Development CHECK selected.

Regards,

Milind Thorat.