This error means that
When using the AccountRight application itself (and having the flag set), attempting to create an Invoice against a Customer that has Stop Credit will provide a warning but will still allow creation of said Invoice.
When attempting to create an Invoice via the API in the same scenario, we instead get a SaleEvent_CreditOnHold Error and the creation is aborted.
In short there is a stop credit flag that has been set, so an invoice cannot push to MYOB for this customer