title: System.Web.Script.Serialization.JavaScriptSerializer' is not defined VS 2019
body: <p>I am creating a project in .net core 3.1  i am getting error in following line</p>
  
  <pre><code> using System.Web.Script.Serialization;
   jsonPayload = new JavaScriptSerializer().Serialize(interopMessageModel);
  </code></pre>
  
  <pre><code>Severity    Code    Description Project File    Line    Suppression State
  Error   CS0234  The type or namespace name 'Script' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)   
  Severity    Code    Description Project File    Line    Suppression State
  Error   CS0246  The type or namespace name 'JavaScriptSerializer' could not be found (are you missing a using directive or an assembly reference?)  
  </code></pre>
  
  <p>I found one sol <a href="https://stackoverflow.com/questions/19467109/how-to-fix-error-type-system-web-script-serialization-javascriptserializer-is">here</a> but did not understand how to resolve it for VS 2019</p>