Determination Account not possible for KBS

Hi Experts,

My client has a PO with Position Type D (Services) and Account Assigment category Q (Project Make to Order), when he made the service entry they could not release it because systems says " Account determintation for KBS is not possible". However they could do goods entries in others PO with Q but for materials instead of services, as they want to do now.

I entered into trx. OBYC and I notice that KBS does not have selected the opction "Account DEtermination", but I know that this correspond to SAP standard procedures. I do not think that I have to change this in SPRO.

Whan do you think?

Thanks.

Sil