InvalidCastException When using ActiveX in C# project

Question

Dear all trader and API Gurus,

Thank you in advance.

Background:

1. Visual Studio 2010, C# Language, ActiveX OCX API as reference of project.

Answer 1

//Try changing the way that you implement the Interface / Clase where you have 
// -- var auduse = new Contract();

//depending on boxing and unboxing from this point try to reverse it and do the following
IContract iaudUse = new Contract();
//then you would use iaudUse. what ever method in the Interface that you are wanting to use.