Upon rebuilding the solution to a file in Visual Studio exported from Construct 2 I received errors:
MSB3774 Could not find SDK "Microsoft.WinJS.2.0, Version-1.0"
MSB3774 Could not find SDK "Microsoft.WinJS.2.1, Version-1.0"
Open Visual Studio
Click File->New Project
Click Windows
Click Windows 8
There will be an option there to install the Windows 8.1 tools.