AssemblyBlockedException
Represents FileLoadException having HRESULT value of 0x80131515. 
            Throw this when we need to instruct the user to "unblock" the downloaded assembly.
            
using System.IO;
namespace DynamoServices
{
    internal class AssemblyBlockedException : FileLoadException
    {
        public AssemblyBlockedException(string message)
            : base(message)
        {
        }
    }
}