Internal requisition

Need help on the inventory. We have a scenario like this.

1. One Ledger, One LE and One operating unit

2. Two Inventory organizations.

One inventory organization(Org A) will always procure from suppliers

One inventory organization(Org will always procure from OrgA

I have created one master inventory organization and two inventory organization OrgA and OrgB. Assigned item with all the three organizations. OrgA the item is made purchase enabled and Org B is internal order enabled.

When raising the requisition in iprocurement  from OrgB getting error when selecting the item 'The system could not determine the internal source for item. Contact purchasing administrator to define appropriate sourcing rules'