[Closed] dotNet – OLE starts and stops right away

OK, this is a somewhat complicated setup, please bear with me:

I have a C# library (taken from http://sourceforge.net/projects/dotmat/ ) that calls a 3rd party math app (Matlab) through OLE. Whenever I try to do that with 3ds Max 2012, the OLE instance starts without errors but also stops right away. Doing the same thing in a standalone C# project works fine… and now I have run out of ideas how to get this working.

Here are a few more details:

The C# code that links to the 3rd party API is

	public class MATInvoke
	{
		#region Engine Functions
        [DllImport("libeng.dll")]
        internal static extern IntPtr engOpen(string startcmd);
        // ... 
        }

and the code to call this within the dotNet class is

	public class EngMATAccess: IDisposable
	{
		public EngMATAccess() : this(4096)
		{		
		}
		
		public EngMATAccess(int buffersize)
		{
			engine = MATInvoke.engOpen(null);
			buffer = IntPtr.Zero;
			resultBuffer = false;
			BufferSize = buffersize;
			BufferingActive = true;
                }
         // ...
         }

which I compile with Visual Studio 2010 into EngMATLib.dll for use in 3ds Max.

Now, within 3ds Max, I call this…

dotnet.loadassembly @"D:\EngMATLib\bin\x64\Release\EngMATLib.dll"
ml = dotnetobject "EngMATLib.EngMATAccess"

… which causes the MATInvoke.engOpen(null) function to be called, which then starts the OLE application but it exits immediately again, returning a NULL pointer.

When I try the same thing using C#

		private void Form1_Load(object sender, System.EventArgs e)
		{
			mat = new EngMATAccess(4096);
		}

things work just fine! I get a proper pointer, the OLE object is up and running and can be used just fine.

ANY ideas or suggestions what I could do to get this working would be HIGHLY appreciated!

Thanks
– MartinB