Building to UWP, editor shows the following error:

Assets\EndpointTest.cs(9,9): error CS7069: Reference to type 'EndPoint' claims it is defined in 'System', but it could not be found

---
using UnityEngine;
using UnityEngine.Networking;

public class EndpointTest : NetworkManager{
void Meh(){
System.Net.EndPoint test = null;
secureTunnelEndpoint = test;
}
}
---

Taking out the set of secureTunnelEndpoint will allow it to export properly. Even using System.Net.EndPoint variables is okay, just not accessing this particular variable. The NetworkManager should work as expected on Windows 10 Unversal apps.

Tested on 5.2.4f1, 5.3.1p3, 5.4.0b3.

Repro steps:
1. open "EndpointTest.zip"
2. build to UWP. Observe the console for errors.