10000882 
Message
Item is not a purchase item
Diagnosis
You have tried to create a purchasing document for an item that is not specified as a purchase item (the option Purchase Item in 
Inventory 
Item Master Data General Area
is not selected).
You have opened the purchasing document, specified a vendor, and in the Contents tab, in the Item No. column you have opened the List of Items window
The option Purchase Item in the Item Master Data record of the specific item was deselected
You have chosen this item from the List of Items window.
Procedure
You can create purchasing documents only for items that are specified as purchase items.
Recommendation
If it has been awhile since you have opened the List of Items window until you have actually chosen the item, close the List of Items window and open it again to refresh the display. If the status of an item has been changed, and it is no longer purchase item, this item does not appear in the refreshed list.