The problem is that the order is in the incorrect state, usually it is set to a status of completed, so this needs to be changed.
Select the Sales Tab
Click on Status Change, Change Sales Order Status
Enter the Order Number, Save
Click on Release Order
Get message this order has already been invoiced,click on OK
Confirm that you want to release the whole order?.
Enter Reason code, then click on Save
You can then do the Reverse Despatch
To complete the order afterwards Repeat 1 to 7 clicking on Complete Order at Stage 4
