Common Language Runtime detected an invalid program.

Description

A file that is part of Windows or the application is corrupt.

Possible Causes

This error indicates than an executable or DLL file has gotten corrupted and needs to be repaired.

Recommended Fix

Perform a repair of .NET using the Programs control panel (or the .NET installer) and a repair of the application.  This should replace any corrupted files with their correct versions.  

https://www.pdq.com/blog/how-to-repair-or-reinstall-net-framework-3-5/