Symptoms
When you recompile a Microsoft .NET Framework 4.5.1 application that uses .NET portable libraries to target the Microsoft .NET Framework 4.5.2, you receive the following error message during compilation:
The type '{type}' is defined in an assembly that is not referenced. You must add a reference to assembly '{assembly}'.
Note In this error message, {assembly} represents one of the actual files that is found in the "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.2\Facades" folder.For example, the error message resembles one of the following messages:
The type 'System.Object' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
The type 'System.Attribute' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
Resolution
To resolve this problem, install the updated version of the Microsoft .NET Framework 4.5.2 Developer Pack. For download information, see Microsoft Knowledge Base article 2901951.
