title: asp.net core project occurs MissingMethodException
body: <p>I create a new project with ASP.NET Core Web Application(.NET Core). 
  And it can work after building and running it. </p>
  
  <p>I create a class library with .NET Core and move the files under Service folder in the web project to the library, then add the reference and change namespace in the controllers. </p>
  
  <p>It occurs MissingMethodException after registering a new user.<br>
  Asp.net core project seems not able to use class library outside the web project. </p>
  
  <p>The detailed message is as the below.</p>
  
  <p><a href="https://i.stack.imgur.com/23LdT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/23LdT.png" alt="enter image description here"></a></p>