This problem is about some fields that are declared double and often is null in the database. Using findAllBy to receive a list then fails if some of the fields are null. I tried with changing the type to Double but then I get problems when I do arithmetics on them. If the value is null the Double can't decide which converter it should use. I don't know if there is any way to convert nulls in the domain before they are set. Example of error:
Caused by: org.hibernate.PropertyAccessException: Null value was assigned to a property of primitive type setter of com.buffer.ProdBuffer.makeInquiry
You should always use Double in your entities/domains; unless you have a nullable: false constraint at work, even then it's a good practice, nonetheless.
However, you need to handle null by yourself in your calculations, probably by making that 0 or 1, you know it better. For more suggestions, post the code snippet.