BMXAA5419W Intra-class joins and non-nullable properties were not deleted.\n\n * Before you can delete properties that are joined, you must break the link between the two \n tables to which the properties belong. You can then delete one or both properties.\n\n * If a property is required (that is, it is defined as not null), you can delete it only if \n you delete all other properties that belong to the same table.