why my C# DLL not worked in MQL programming language when I Import it?

Question

Hi I Created DLL with C# .NET Framework 4.5 and the build on Any CPU. I want user this DLL to read the motherboard and Hard Drive Serial number. After I copy my DLL to the Library Folder of Meta trader (for mql4 and 5) and import it to my Custom Indicator My app has not the error on the compile but when I run with the debugging on the real data, the message box show the:

critical error occurred. debugging is stopped.

Also when I drag and drop it on chart the Indicator load Successfully but show nothing.(when I remove DLL the Indicator worked fine).

using System.Management;


namespace SystemInformation
{
    public class SystemInfo
    {
        public string GetMotherboardSerialNumber()
        {
            using (var searcher = new ManagementObjectSearcher("SELECT SerialNumber FROM Win32_BaseBoard"))
            {
                foreach (var queryObj in searcher.Get())
                {
                    return queryObj["SerialNumber"].ToString();
                }
            }
            return string.Empty;
        }

        public string GetStorageDeviceSerialNumber()
        {
            using (var searcher = new ManagementObjectSearcher("SELECT SerialNumber FROM Win32_DiskDrive WHERE MediaType='Fixed hard disk media'"))
            {
                foreach (var queryObj in searcher.Get())
                {
                    return queryObj["SerialNumber"].ToString();
                }
            }
            return string.Empty;
        }
    }
}

and this is my custom indicator part for DLL:

#import "SystemInformation.dll"
string GetMotherboardSerialNumber();
string GetStorageDeviceSerialNumber();
#import

int OnInit()
  {

      
      string motherBoard = GetMotherboardSerialNumber();
      
      string hardDrive = GetStorageDeviceSerialNumber();
      Alert(motherBoard + " " + hardDrive);
       return(INIT_SUCCEEDED);
}

also when I set debug point on OnInit. when the pointer read the string motherboard line the app is crashed. I also checked the option, tools for checked the allow DLL import and it is checked. and I test my DLL on the one test C# program and worked fine. how can fix this? please help.