Download from FTP with Hololens?

Hi everybody,

I would like to download files from a FTP-Server and do some magic with the data.

The application should run on the Microsoft Hololens. I am using Unity 2017.2 with the MixedRealityToolkit "2017.2.1.1 Patch Release".

In Unity everything works fine, but as soon as I try to build the application I receive 5 errors like: "The type or namespace name "FtpWebRequest" could not be found (are you missing a using directive orassembly reference?)"

I am using the Runtime Version "Experimental (.NET 4.6. Equivalent)" and the Api Compability Level ".NET 4.6"

This is the code of my main script:

 using UnityEngine;
 using System.IO;
 using System.Net;
 using System;
 
 
 public class UpdateFtfFtp : MonoBehaviour
 {
     public float JsonReadInterval = 1;
     public int AgvNumber;
 
     private const string Host = "ftp://192.168.2.101/";
     private string _remoteFileName;
     private string _localFileName;
 
     private const int bufferSize = 2048;
 
     // JSON coords are in mm, table dimension is 2000mm x 1000mm
     // Y axis on the table corresponds to Z axis on the map
     // 0, 0 is at -0.036, 0.442 (local) on the map
     // 2000, 1000 is at -0.526, 0.131 (local) on the map
     // (assuming real coords are in the center of the FTF)
     // This results in the following ratios for translating real to virtual coords
     private const float ZeroX = -0.036F;
     private const float ZeroY = 0.442F;
     private const float RatioX = -0.000245F;
     private const float RatioY = -0.000311F;
 
     private float _timer;
 
     // Use this for initialization
     public void Start()
     {
         _remoteFileName = "AGV" + AgvNumber + "Status.json";
         _localFileName = "Assets\\JsonStream\\" + _remoteFileName;
         LoadJsonData();
     }
 
     // Update is called once per frame
     public void Update()
     {
         _timer += Time.deltaTime;
 
         if (_timer >= JsonReadInterval)
         {
             LoadJsonData();
             _timer = 0;
         }
     }
 
     private void LoadJsonData()
     {
         DownloadJson();
 
         var jsonString = File.ReadAllText(_localFileName);
         var ftfData = FtfData.FromJson(jsonString, AgvNumber);
 
         transform.eulerAngles = new Vector3(0, 0, ftfData.Gyro);
         transform.localPosition = new Vector3(
             ZeroX + RatioX * ftfData.PosX,
             transform.localPosition.y,
             ZeroY + RatioY * ftfData.PosY
         );
     }
 
     private void DownloadJson()
     {
         var request = (FtpWebRequest)WebRequest.Create(Host + _remoteFileName);
         request.Credentials = new NetworkCredential("pi", "123");
         request.Method = WebRequestMethods.Ftp.DownloadFile;
         var response = (FtpWebResponse)request.GetResponse();
         var ftpStream = response.GetResponseStream();
         var localFileStream = new FileStream(_localFileName, FileMode.Create);
 
         var byteBuffer = new byte[bufferSize];
         var bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
 
         try
         {
             while (bytesRead > 0)
             {
                 localFileStream.Write(byteBuffer, 0, bytesRead);
                 bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
             }
         }
         catch (Exception ex)
         {
             Debug.Log(ex.ToString());
         }
 
         localFileStream.Close();
         ftpStream.Close();
         response.Close();
         request = null;
     }
 }

Do you know if it's possible to request data from a FTP-Server with the Hololens?

All errors seem to be related to missing type or namespaces, in particular multiple errors from the System.Net namespace. Is it possible that I am missing a DLL or that the HoloLens does not support some libraries?

I am glad for any help. :)