XK07 Vendor account group change for a Vendor

Dear All,

When i try to change the vendor account group for a vendor in XK07, i get the following error.

Partner function OA is not available at level Purchasing organization in schema

Message no. WY155

Diagnosis

Partner function OA is assigned to your vendor at level Purchasing organization. Partner schema is valid at level Purchasing organization in the new account group ZBON you selected. Partner function OA is not defined in this partner schema.

By changing the account group, partner functions were assigned to your vendor which are not allowed.

System Response

A change to the account group is not allowed.

Procedure

Please change the partner schemas for the account groups in Customizing

Please advice how should i proceed?

Regards