IncomeAccountFreight Linked Account is required if charging freight
The problem here is that an invoice with freight on it will not sync over to MYOB. The error above comes up in the error logs.
1) Go to Settings - MYOB Settings and take note of the account in "Freight Sales Account"
2) Log into MYOB through your AccountRight software
3) Go to Setup - Linked Accounts - Sales Accounts
4) Tick "I charge freight on sales", and select an account in this area
5) Click OK to save.