Uncharged orders usually pop up when there are errors with credit card issuers or payment processors. For some reason, when we go to capture a charge after the initial authorization, the capture fails. This happens sometimes.
When it does, the uncharged order will appear on this page. In order to complete the charge, you can click on the Retry Charge button to see if that solves the issue. If not, you can log in to your payment processor's website and attempt to re-process the charge from there.
If that fails, too, you need to reach out to the customer directly and ask them to use a different credit card for the order.