Booking in Exchange does not work for items with multiple prices.

The booking of products with multiple prices does not always work. If you have enabled multiple prices for a product and you also have multiple barcodes linked to this product with prices, but Exchange states that this product cannot have multiple prices, an error message will occur during the booking process. 

You must first remove all barcodes associated with the additional prices from the product. Then you can set the "Allow multiple prices" indication back to "No" on the Sales tab. After that, you can book this product in Exchange.