At PO lines, we generally face this issue where system pop ups the following message;
To resolve this issue, navigate to;
Product information management -> Common -> Released product details form -> Select an item & click Edit -> Select Fast tab ‘Purchase’
Select ‘No check’ to avoid the warning message.
Just another use of this option; if you want to select an item only for approved vendor, select ‘Not allowed’ in Approved vendor check method field.