Visual Studio compilation error UWP

Question

I am building a UWP app on Visual Studio 2015 Update 1. I am encountering errors where Compiler says "async is not a feature of C# 4.0 use 5.0 or greater", "Windows namespace cannot be found"

Error CS8025 Feature 'async function' is not available in C# 4.
Error CS0246 The type or namespace name 'ConnectionProfile'

However upon closing my solution and reopening it these errors disappear. And my app runs(in debug mode). However after a few debug sessions the problem resurfaces.

To Correct any errors on my part I Have :

1> Reset VS user Settings

2>Reinstalled VS

3>Reset Windows 10

But the problem doesn't want to go. I am using Windows 10 Home Edition and also I don't use insider builds. Recreated my project from scratch

As a result even the most basic tasks performed in my code appear erroneous.

Answer 1

Can you revise if you have installed Microsoft.NETCore.UniversalWindowsPlatform as a nuget package? Wen you create a new uwp project, automatically its added.

I had similar problem that some namespaces was not encountered and the answer was this nuget package.