I've face very odd situation now.
Purchase order has specific Network order & Activity Number in 'Account Assignment' tab. Of course Network has 'REL' status which can be post cost.
Then I can post cost to Network Order in FB01 transaction.
But if I save Accepted SES in ML81N system shows KI 235 error message (Account ***** requires an assignment to a CO object ) in 'Error Log of Acceptance Posting'.
I've checked assignment of Item Category 'D - service' and Account Assignment Category 'N - Network' in OMG0 transaction (IMG).
One more odd thing is ... PO with AAC 'K - cost center' and 'D' also can't save SES in ML81N.
Is there any gurus have any clue for this?
Thanks in advanced,