10000521 
Message
To generate this document, first define the numbering series in the Administration module
Diagnosis
You have created a delivery and copied it into an A/R invoice. You tried to add the A/R invoice, but since the document numbering setting for the document type is incorrect, the document was not added to the database.
Procedure
Choose
Administration 
System Initialization Document Numbering 
.In the Document Numbering – Setup window, for the requested document type, enter a value for the Last No. field that is greater than the value in the Next No. field.