I'm building a Integration Studio Action using sharpPDF Library.  I've build the same extension several times, and I've got the same error each time.

I go in and use the Nuget package manager to install the sharpPDF library successfully.  I can open and close it as much as I want and can get in and work on the extension.  However, when I go back in the next day (and this has happened on every extension where I've installed this library), it says it's missing the references and there is NO app.config or package.config file.

I'm not sure why this is happening or how to resolve it.  I've made many extensions in the past and have never had this issue.