When Releasing from PWB, get message: Item is master scheduled, can not be released

Hi -

In ASCP, for the majority of the finished good products, our users define a production schedule offline on Excel spreadsheets (ignoring the forecast and sales order demand).  We are using the Self Service Loads to load the finished goods production schedule as Planned Orders into the ASCP plans (instead of manually entering the planned orders).  We upload the data using the 'PlannedOrderSupply' template.

When we define the ASCP plan, in Plan Options. we specify the demand schedule that holds the uploaded planned orders.  We then run the plan to plan for subassemblies and raw materials.  However when we try to release the planned order for the finished goods, we receive an error message "Item is master scheduled, can not be released".  We expect that we would be able to release the manually loaded planned orders as work orders to build the finished good products.  Is there another approach to this that we are missing?