This is a placeholder bug.
A customer reported that taking a Web API 2.0 site, and updating the nuget package for web api client succeeded but left the site broken, because the web API 1.0 package was not updated.
A customer reported that taking a Web API 2.0 site, and updating the nuget package for web api client succeeded but left the site broken, because the web API 1.0 package was not updated.