Major Description
the DemoShipping.xml data file uses ShipmentCostEstimates that share the same QuantityBreak entities, this isn't supported in the UI when attempting to delete a ShipmentCostEstimate as the code attempts to delete related QuantityBreaks causing foreign key exceptions. The service code that fails is removeShipmentEstimate in ShipmentServices.java.
I kept the priority as major because this causes a stumbling block for newcomers using the Production Setup Guide.