Using C# delegate to transfer progress

I have created a Matlab calculation routine and compiled it to a .NET assembly. This assembly is used in a C# web-application. To give feedback of the progress from the Matlab routine I want to call a method in C#. For this I use a delegate.

namespace NetSample
{
    public delegate void Del(double com);    

      public class NetSample
      {
          public Del MyDel;
          private MatlabCalculator matlab;

          public NetSample()
          {            

              matlab = new MatlabCalculator();

          }

          public void Run()
          {
              matlab.test();
              matlab.Dispose();
          }

      }

}

Within Matlab I register the method Print to this delegate:

function test
    NET.addAssembly('C:\Program Files\Matlab\R2015a\extern\examples\NET\NetSample\bin\Debug\NetSample.dll');
    %NET.addAssembly('NetSample.dll');   
    myClass=NetSample.SampleMethods;
    myDel=NetSample.Del(@myClass.Print);

      for ii=1:100    
          fprintf('Call delegater');
          myDel(ii);
      end
      myDel.delete();
  end

This routine works except that when the C# routine has stopped it gives an error as given in the attached file. Can you give me advise to correct this problem?

[Walter Roberson]

No file appears to be attached?