Diagnosis
The incompletion check reveals, for analysis purposes, any incompletedocuments.
The message contains:
A description of the incomplete document
A technical entry, telling you which table field has been checked
A the error groups in the transaction from Customizing for Incompletion Log.

Procedure
One solution is to deliver the affected document in the screen (Createdelivery with reference to order), and to edit and save the deliveryfollowing the menu path: Edit -> Incompletion.
In certain circumstances, you can change Customizing so that
the checked field is no longer assigned to the error group
or
assign another error group to the document type /item category
or
permit the delivery as a subsequent function.