Hi, I'm experiencing the exact same error.
I believe the error is related to the .net framework backwards compatability. Although I am not sure, this started happening after I installed Visual Studio 2017 and .net 4.5
Additional information: The following error occurred while determining how to marshal the parameters of member 'OnCmd' of type 'EdmLib.IEdmAddIn5': System.TypeLoadException: Could not load type 'EdmLib.EdmCmdData' from assembly 'ReviewReports, Version=22.214.171.124, Culture=neutral, PublicKeyToken=null'. This is most likely due to an incompatible MarshalAs attribute on one of the parameters.