Square 9's GP Connector pushes documents to GreatPlains 2011, 2013, 2014 and 2018. When pushing these documents, a number of errors may be returned from GreatPlains; below are the messages you may receive, and what they mean.

Error Message Returned	Meaning
QuantityInvoiced is greater then the amount remaining to match.	For Purchasing Invoices, the Invoice pushed contains line items that exceed the outstanding items on the Purchase Order. For example, the Purchase Order expects 10 Blue Pens, we received 10 Blue pens and they have been billed for all items, but an invoice is pushed for items exceeding those originally ordered.
VendorDocumentNumber already exists.	The Invoice Number/Vendor ID have already been used and exist in GreatPlains, they must be unique.
The Purchase Order has been closed or cancelled, you cannot receive against it.	The Purchase Order you're receiving against is not open in GreatPlains.