Could not load file or assembly 'System.CodeDom, Version=4.0.2.0... or one of its dependencies. The system cannot find the file specified

trigger reason

When installing IronPython in NuGet, it was always prompted that there was a lack of dependencies, so I directly changed the dependency behavior under the installation and update options from "minimum" to "ignore dependencies" during installation, resulting in an error when the program was compiled.

Solution

Find the installed solution package, scroll down with the mouse, and you can see its dependencies:

find the reason, you need to change the NETFramework of the project to V4.6.2 to support

changing the target framework to .NET Framwork 4.6.2 and then compile, the problem solve.