System.Net.IPEndPoint does not exist in target framework for windows phone 8 build but it does exist

Unity Engine
1

Exact error:

Reference rewriter: Error: method System.Void System.Net.IPEndPoint::.ctor(System.Net.IPAddress,System.Int32) doesn’t exist in target framework. It is referenced from SnapClient.dll at System.Void SnapClient.Client::Connect(System.String,System.UInt16).
UnityEngine.Debug:LogError(Object)
PostProcessWinRT:RunReferenceRewriter() (at C:/buildslave/unity/build/PlatformDependent/WinRT/SharedSources/CSharp/PostProcessWinRT.cs:503)
PostProcessWinRT:Process() (at C:/buildslave/unity/build/PlatformDependent/WinRT/SharedSources/CSharp/PostProcessWinRT.cs:98)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()

I checked and it does exist in the framework and it was in fact working with Unity 5.0 but is not working with Unity 5.1.

I can no longer build the project because of this. Anybody else experienced this as well?

2

Found the cause here: