CO validations purchase order commitement for investment order

Hello,

I need to set up a CO validation: the requirement is not to allow creating purchase orders in company code xyz with fixed assets and investment order (the commitment is active on the order type) with account assignment category 'A' (non-valuated GR).

I tried this way in OKC7: with no luck

Prerequisite:

COBL-BUKRS = '1234' AND COBL-GLVOR = 'RMBE' AND

COBL-SCOPE = 'INVST'

Check:

COBL-WEUNB <> 'X'

Message: error message

Contr. area = 1234 event = 1 validation = xyz active = 1

I also tried:

Prerequisite:

COBL-BUKRS = '1234' AND COBL-GLVOR = 'RMBE' AND COBL-SCOPE

= 'INVST' AND COBL-WEUNB = 'X'

Check:

FALSE

Message: error message

Contr. area = 1234 event = 1 validation = xyz active = 1

I did not make it to work.

Please kindly advise how to prevent the PO's with fixed assets for some company codes from being created with non-valuated GR.

Thank you,

Inna