If you get a message saying “Unable to pack stock as it is RESERVED. Please contact your stock controller to have the stock released” when you try to pack the order.
Stock cannot be packed if one or multi items are reserved and locked from using in sales order fulfillment.
In order to use that items follow these steps
1. Double click on the item in the dispatch register line item.
2. Go to > Flags > untick the item/items in order to pack this item.
Before you untick item double check if there is any reason for item to be reserved and locked.