850 Inbound is getting into error
I am trying to import 850 inbound and it is getting into below error.
Order Number : Line Number :
Message :The order source does not exist or is not enabled. Please enter a valid order source.
Order Number : Line Number :
Message :Invalid ORIG_SYS_DOCUMENT_REF. Please enter a not-null value.
Order Number : Line Number :
Message :You are trying to insert an existing order or update an order that does not exist. Please enter a correct operation code.