When you build a Windows Embedded Compact 2013 run-time image on Windows 8.1. You may receive an error message that resembles the following:
C:\wince800\public\common\oak\misc\sources.ce(6) : fatal error
U1050: Error: Microsoft .NET Framework v4.x must be installed on your machine.{log=”c:\wince800\build.log(132)”}
U1050: Error: Microsoft .NET Framework v4.x must be installed on your machine.{log=”c:\wince800\build.log(132)”}