If you see the message “Order was not created. Reason: This product is currently out of stock" this means that when M2E Pro was trying to create order in Magento, the product had the status "Out of Stock", so the order could not be created.
When the status of the product changes to "In stock", you can manually create Magento order for the particular sale. To do so, navigate eBay/Amazon/Walmart > Sales. From the action drop-down menu of the appropriate order record, choose Create Order. When Magento order is created you will see the message “Magento Order was created”.