.Net Add-In The add-in has another interface version

I'm learning how to make .Net add-ins for sdl passolo 2016 and I have some trouble adding add-ins. For learning purposes I decided to add the DnContextViewer from the AddIns sdk to see what it does. As said in the documentation, I put the dll in a folder that has the same name and I put the .paiconfig file in the folder too (Check the last photo to see my config file). Once I did that, I started passolo and the add-in wasn't automatically detected and I decided to add manually by selected the DnContextViewer dll. Unfortunately, the add-in didn't load... Passolo is saying that the add-in has another interface version (see second photo). What is the meaning of the message and how can I make the add-in work?