It came to my attention today that the example code in the latest release of nspectre will throw an exception if you don't have a "d" drive (that can be written to.) It's simple to resolve – change the path to a valid one (line 57 in Class1.cs.) The line is there to demonstrate how much easier it is now to save the generated code. In the next release, I will comment that line out in favour of the line that doesn't save the generated code. This issue only affects the sample code.