10/18: Posting issue has been fully resolved. Thank you for your patience as we worked over this.
10/13: When posting orders to Quickbooks Online (QBO) and it error out with "QBReprocessedOrder: 6000 Business Validation Error: Add a line item to continue.", Please retry posting that order twice. This will allow you to post the order successfully. We are still investigating this issue. It appears to be an issue with Quickbooks Online returning this error and we are working with them to get it resolved as soon as possible. Thank you for your patience.