BPM to Check if customer price list empty

I am working on a bpm to prevent save on a customer record if the Price List is missing. I am having issue getting it work correctly. I will run the query and check but then i cant save as it is in a different table any ideas on this?

Customer is maintained independent with the customer price list. I think You can change your process by controlling “Active” status (sold to, bill to, ship to) of customer only have Customer Price List. Don’t ignore to save new customer because sometimes Price list is not ready right now when you get the customer information.