You received this error message because one or more Transaction IDs were duplicated on the Sales Confirmation page. This means there is an issue with either the way you are sending us the Transaction ID or with how we are recording the sale. In order to ensure accurate sales reporting, we need a unique Transaction ID with every sale.
Please ensure that you are passing us the Order/Confirmation number from the sale. If you are unable to pass us this information, please provide a unique or random number instead. Click here for more information about the Criteo OneTag on the Sales Confirmation page.