Errors related with MYOB API
Error: Request failed with status code 401/404/500, Error: Issue creating customer, Error: Issue creating product (Request failed with status code 300), Error: An exception was thrown that was not handled correctly.
If you received any of these error messages above, it means that there was a MYOB API failure.
First, select the order with this error.
Click the drop-down option beside "Sync to Myob" and select "Re-Sync".