NTVDM CPU遇到了非法指令

I have encountered a rather odd error that I do not understand. I created a C# console application that was designed to just be a test to see if my web service was working from outside my network. All it did was try and connect to the webservice, output each stage to the console and write it to a text file so they could send me the logs.I have encountered a rather odd error that I do