Symptom
QuickBooks Online error Please select item business validation error.
Cause
Here are the known causes for this error:
Webgility tries to post the shipping cost to Quickbooks, but that option is not enabled in QuickBooks.
An order item does not have an income or expense account associated with it in QuickBooks.
An additional item is sent as a line item to QuickBooks and not marked as sellable within QuickBooks.
Resolution
Correct the settings within QuickBooks.