Vendor code “Vendor number” is not authorized for “item number”

Good day everyone! This is a tip for developers who are struggling with mysterious warning messages when creating a Purchase Order. When adding an item to a purchase order, you might get the  error/warning: Vendor code “Vendor number” is not authorized for “item number” This is a configuration error. In AX 2012, you can specify which items can be purchased from what vendors. This prevents the purchasing/buyers departments from purchasing items from a variety of vendors...(read more)