MEF CS0234: The type or namespace name 'Composition' does not exist in the namespace 'System.ComponentModel' (are you missing an assembly reference?)
asp.net, c#
Solution
First of all (if it's needed) Open your project in Visual Studio 2012 or later, choose Manage NuGet Packages from the Project menu, and search online for the Microsoft.Composition package.
Right-click on your Project and select "Add Reference". Find System.ComponentModel in the Framework list and add it or the applicable sub assembly.
Thats's all I did when I faced this problem.
Problem
I have added in ComponentModel.Composition; assembly .But showing this error for using System.ComponentModel.Composition; and reference for the assembely still gets the error CS0234: The type or namespace name 'Composition' does not exist in the namespace 'System.ComponentModel' (are you missing an assembly reference?)