You can't create purchase order lines with the UOM set to the item's secondary UOM.

My primary and sec.UOM is same, for ex : Each, there are few cases we have like this.

When i create the Purchase order the primary and sec.UOM is getting defaulted same and i am getting the above error message.

As a work around i have changed the primary and submitted the PO, but is this a valid error or any setup is missing ?