Non-nullable property 'Name' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Name' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'FileName' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Pages' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Name' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Category' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Notes' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Product' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'ProductName' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.