Error send image from client to WCF Server C# (Invalid length for a Base-64 char array)

Hallo i have one wcf server and one client and i want to send/receive image from/to client as string (convert to base64). I send from server to client already and works. I want to send from client to server and get error: Invalid length for a Base-64 char array. Probably the error is in xml file.

Here is my code:

Server side: (WCFService.cs)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Web;
using System.Drawing;
using System.IO;
using System.Runtime.Serialization.Json;
namespace Services
{
    public class WCFService : Services_Form, IWCFService
    {

        public string ImageToBase64(Image image)
        {
            using (MemoryStream m = new MemoryStream())
            {
                image.Save(m, image.RawFormat);
                byte[] imageBytes = m.ToArray();
                string base64String = Convert.ToBase64String(imageBytes);
                return base64String;

            }
        }

        public Image Base64ToImage(string base64String)
        {
            // Convert Base64 String to byte[]
            byte[] imageBytes = Convert.FromBase64String(base64String);
            MemoryStream ms = new MemoryStream(imageBytes, 0,
              imageBytes.Length);

            // Convert byte[] to Image
            ms.Write(imageBytes, 0, imageBytes.Length);
            Image image = Image.FromStream(ms, true);
            return image;
        }

        //RECEIVE IMAGE
        public string getimage()
        {
            return ImageToBase64(pictureBox1.Image);
        }

        //SEND IMAGE
        public string postimage(string im)
        {
            pictureBox2.Image = Base64ToImage(im);
            return "Ok";
        }
    }
}

(IWCFService.cs)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Web;

namespace Services
{

    [ServiceContract]
    public interface IWCFService
    {
        [OperationContract(Name = "image")]
        [WebInvoke(Method = "GET",
            ResponseFormat = WebMessageFormat.Json,
            BodyStyle = WebMessageBodyStyle.Bare,
            UriTemplate = "getimage")]
        string getimage();

        [OperationContract(Name = "image2")]
        [WebInvoke(Method = "GET",
            ResponseFormat = WebMessageFormat.Json,
            BodyStyle = WebMessageBodyStyle.Bare,
            UriTemplate = "postimage?Image={im}")]
        string postimage(string im);

    }
}

The Server Form

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Threading;
using System.Data.SqlClient;

namespace Services
{

    public partial class Services_Form : Form
    {
        ServiceHost host;
        string WCFPort;

        //SERVER FORM
        public Services_Form()
        {
            InitializeComponent();
        }

        private void StartWCFServer()
        {
                if (host == null)
                {
                    Uri baseAddress = new Uri("http://localhost:"+WCFPort+"/");
                    host = new ServiceHost(typeof(WCFService), baseAddress);
                    host.AddServiceEndpoint(typeof(IWCFService), new WSHttpBinding(), "Services");
                    try
                    {
                        host.Open();

                    }
                    catch
                    {
                        MessageBox.Show("ERROR");
                    }
                }
                else
                {
                    MessageBox.Show("Change PORT");
                }
        }

        private void btn_StopServer_Click(object sender, EventArgs e)
        {
            if (host != null)
            {
                host.Close();
            }
            else MessageBox.Show("Server already closed!");
        }

        //START SERVER BUTTON
        private void button1_Click_1(object sender, EventArgs e)
        {
            WCFPort = "8000";
            StartWCFServer();    
        }
    }
}

Server's App.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.serviceModel>

    <services>

      <service name="Services.WCFService" behaviorConfiguration="ServiceBehaviour">

        <endpoint bindingConfiguration="webHttpBindingDev" address="" binding="webHttpBinding" contract="Services.IWCFService"  behaviorConfiguration="web"></endpoint>

      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="ServiceBehaviour">
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="false" />
          <serviceDebug httpHelpPageEnabled="true" includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="web">

          <webHttp />

        </behavior>
      </endpointBehaviors>
    </behaviors>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true"/>
    <bindings>
      <webHttpBinding>
        <binding name="webHttpBindingDev">
          <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647"  maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
        </binding>
      </webHttpBinding>
    </bindings>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <directoryBrowse enabled="true" />
  </system.webServer>
</configuration>

Now the client side:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.Serialization.Json;
using System.Web.Script.Serialization;
namespace Διαχείριση
{
    public partial class Administator_Form : Form
    {
        string IpAddress = "localhost";
        string Port = "8000";


        //CLIENT FORM
        public Administator_Form()
        {
            InitializeComponent();
            try
            {
                WebRequest request = WebRequest.Create(UrlTag(""));
                WebResponse response = request.GetResponse();  
            }
            catch
            {
                MessageBox.Show("Error connect to server");
            }
        }

        public string ImageToBase64(Image image)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                // Convert Image to byte[]
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                byte[] imageBytes = ms.ToArray();

                // Convert byte[] to Base64 String
                string base64String = Convert.ToBase64String(imageBytes);
                return base64String;
            }
        }

        public Image Base64ToImage(string base64String)
        {
            // Convert Base64 String to byte[]
            byte[] imageBytes = Convert.FromBase64String(base64String);
            MemoryStream ms = new MemoryStream(imageBytes, 0,
              imageBytes.Length);

            // Convert byte[] to Image
            ms.Write(imageBytes, 0, imageBytes.Length);
            Image image = Image.FromStream(ms, true);
            return image;
        }

        private T GetDataFromServer<T>(string url)
        {
            WebRequest request = WebRequest.Create(string.Format(url));
            WebResponse response = request.GetResponse();
            Stream stream = request.GetResponse().GetResponseStream();
            DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(T));
            T result = (T)json.ReadObject(stream);
            return result;

        }

        private string UrlTag(string tag)
        {
            return "http://" + IpAddress + ":" + Port + "/" + tag;
        }

        //SEND IMAGE
        private void button2_Click(object sender, EventArgs e)
        {
            string myParameters = "";
            myParameters = "?Image=" + ImageToBase64(pictureBox1.Image) + "";
            string responseMessage = GetDataFromServer<String>(UrlTag("postimage" + myParameters));
        }

        //RECEIVE IMAGE
        private void button3_Click(object sender, EventArgs e)
        {
            string img = GetDataFromServer<string>(UrlTag("getimage"));
            pictureBox2.Image = Base64ToImage(img);
        }

    }
}