After uploading an attachment, we are unable to enter a supplier reference number as the SAP is not allowing to enter anything in that box, as the box is uneditable. So we tried saving the invoice without entering the supplier reference number, after doing this step we are displayed an error “Error: Enter supplier reference number” but ignoring that we tried by clicking send. We could not send the invoice even after clicking the send button. The status of the invoice is still “ In Process” which should be “document Sent”.
How can i enter an invoice number in that box, please see the image.