Purchase Order Confirmation greyed out

Issue : You unexpectedly experience that whenever you make a Purchase Order in Microsoft Dynamics AX2012 the Purchase Order is always of the type 'Draft' and Confirmation button is greyed out so you can not make a Purchase Order 

Solution: Try to go to the module 'Procurement and sourcing/Setup/Parameters and note if you have the 'General' parameter 'Activate change management' marked

To enable the Purchase Order confirmation, try to unmark the above parameter and see if your confirmation button is now enabled when you make a new Purchase Order

The reason for this behavior has to do with the Change Management for Purchase Orders feature in AX 2012. You can find more information about this here

http://technet.microsoft.com/en-us/library/hh802989.aspx

Unfortunately there is no easy way to 'correct' an already created Purchase Order in this case where the Confirm button is greyed out because the 'Activate change management' parameter was marked so the easiest would be to delete this Purchase Order and create a new one