I’ve got two sets of enum values that are exactly the same but in different namespaces that I want to be able to cast between. How can I do this as I get an object reference not set to an instance of an object error with my attempt below?

namespace Namespace1
{
    public enum RefundResponseEnum
    {
        AvailableForRefund = 0,
        NotAvailable = 1,
        MainFrameError = 99
    }
}

namespace Namespace1
{
    public class Return
    {
        public Return()
        {
        }       
        
        public RefundResponseEnum Response { get; set; }
    }
}

namespace Namespace2
{
    public enum RefundResponseEnum
    {
        AvailableForRefund = 0,
        NotAvailable = 1,
        MainFrameError = 99
    }
}

namespace Namespace2
{
    public class Return
    {
        public Return()
        {
        }
        
        public RefundResponseEnum Response { get; set; }
    }
}

The following below returns an object reference not set to an instance of an object error.

var namespace2Enum = (Namespace2.Return.RefundResponseEnum)((int)Namespace1.Return.Response);