When an order is in an Unresolved > Missing Order Info status, this means that crucial information regarding the order (name, address, city, state, or zip code) is missing.
To see exactly what information is missing, go to the Orders module, click on the 'Unresolved' dropdown, and then 'Missing Order Info'. This will display all unresolved orders with this error. You can view and update this information from the 'Order Fulfillment' pane on the right, and click 'Recipient'.
This status is rare, as most sales channels require this information to be entered by the customer before the order is placed on their platform. Nonetheless, if you have an order in this status, you will not be able to ship it until you have input this information.