Can't execute external program

Hi. I'm trying to exectute an external program, because of an operation that makes Unity crash. Here's the code I wrote

 {
             //Get the support program directory
             string AssetsPath = Application.dataPath;
             DirectoryInfo parentDir = Directory.GetParent(AssetsPath);
             string ProjectPath = parentDir.Parent.FullName;
             //Call for the external process
             Process Support = new Process();
             Support.StartInfo.WorkingDirectory = ProjectPath + @"Supportprogram\External Context\External Context\bin\Debug\";
             Support.StartInfo.Arguments = file;
             Support.StartInfo.FileName = "External Context.exe";
             Support.Start();
             Support.WaitForExit();
         }

As Input I chose a file and the program has to convert it in another format. Once I run the game and choose the file to use, It returns me this error:

 Unable to start program 'c:\..........exe'. The system cannot find the file specified.

Do someone have any hint how to solve this problem?

I created a new Consol app (.net framework) with visual studio, Into the Unity project folder. Next to he Asset Folder.