PReqs with sales order stock couldn't be adpoted by PO with acc. assignmnt

Question

I use MD50 to generate PReqs for MTO, these PReqs couldn't be adpoted by ME21N with message 06251:
Requisition &, item & , assigned to other order account
but if I use ME21, it's ok. I find the following notes. But I don't understand in my case I don't want change PReqs account assignment, but adpotion is also failed to get account assignment from PReqs.
Refer to  Note 632573 - ME2xN: 06259 if different account assignment in PReq
Summary
Symptom
In Transactions ME21 and ME22, you can change the account assignments for purchase order items with reference to purchase requisitions with sales order special stock or project special stock. This option no longer exists in the EnjoySAP purchase order transactions, the system generates error message 06251:
           Requisition &, item & , assigned to other order account
Other terms
ME21N, ME22N, ME23N, 06251, sobkz,
Reason and Prerequisites
The purchase requisitions were not generated from sales and distribution but created for sales order special stock or project special stock.
Solution
In the EnjoySAP purchase order transaction, you cannot enter an account assignment different from the purchase requisition for sales order special stock or project special stock if you reference to a purchase requisition. You must first change the purchase requisition correspondingly and then call the purchase order again.
Under the above mentioned conditions, also in Transactions ME21 and ME22, the account assignment of the purchase order must correspond to the purchase requisition if the reference to the purchase requisition is created in a schedule line. Unlike in Transactions ME2xN, you can change the account assignment in the purchase order at a later stage.
It is not planned to change the system response

Answer 1

I use MD50 to generate PReqs for MTO, these PReqs couldn't be adpoted by ME21N with message 06251:
Requisition &, item & , assigned to other order account
but if I use ME21, it's ok. I find the following notes. But I don't understand in my case I don't want change PReqs account assignment, but adpotion is also failed to get account assignment from PReqs.
Refer to  Note 632573 - ME2xN: 06259 if different account assignment in PReq
Summary
Symptom
In Transactions ME21 and ME22, you can change the account assignments for purchase order items with reference to purchase requisitions with sales order special stock or project special stock. This option no longer exists in the EnjoySAP purchase order transactions, the system generates error message 06251:
           Requisition &, item & , assigned to other order account
Other terms
ME21N, ME22N, ME23N, 06251, sobkz,
Reason and Prerequisites
The purchase requisitions were not generated from sales and distribution but created for sales order special stock or project special stock.
Solution
In the EnjoySAP purchase order transaction, you cannot enter an account assignment different from the purchase requisition for sales order special stock or project special stock if you reference to a purchase requisition. You must first change the purchase requisition correspondingly and then call the purchase order again.
Under the above mentioned conditions, also in Transactions ME21 and ME22, the account assignment of the purchase order must correspond to the purchase requisition if the reference to the purchase requisition is created in a schedule line. Unlike in Transactions ME2xN, you can change the account assignment in the purchase order at a later stage.
It is not planned to change the system response