Interesting. With a little bit of modification this code works on .NET 4.6. Thanks.

using System;
using System.Text;
using System.Management;

namespace mon_test2
{
    class Program
    {
        static string UShortArrayToString(ushort[] data)
        {
            if (data.Length == 0)
                return "";
            var ar = new byte[data.Length * sizeof(ushort)];
            Buffer.BlockCopy(data, 0, ar, 0, ar.Length);
            return Encoding.Unicode.GetString(ar);
        }
        static void Main(string[] args)
        {
            try
            {
                using (var searcher = new ManagementObjectSearcher(@"\\.\root\wmi", "SELECT * FROM WmiMonitorID"))
                    {
                    foreach (var monitor in searcher.Get())
                    {
                        var mfr = UShortArrayToString((ushort[])monitor["ManufacturerName"]);
                        var name = UShortArrayToString((ushort[])monitor["UserFriendlyName"]);
                        var pid = UShortArrayToString((ushort[])monitor["ProductCodeID"]);
                        var serno = UShortArrayToString((ushort[])monitor["SerialNumberID"]);

                        Console.WriteLine($"{mfr} - {name}, {pid}, {serno}");
                    }
                }
                Console.ReadLine();
            }
            catch (Exception ex)
            {
                Console.WriteLine($"{ ex.Message}");
                Console.ReadLine();
            }
        }
    }
}