Reproduction Steps:
1. Open User's project
2. Open "main" scene
3. Run scene
4. Error is thrown:
ArgumentException: Value does not fall within the expected range.
System.Net.Sockets.Socket.SetSocketOption (SocketOptionLevel optionLevel, SocketOptionName optionName, System.Object optionValue)

Note: The same code does not throw this error on .NET console application.

Expected Behaviour: Identical behaviour as in .NET.
Actual Results: Unity throws SocketException that is not thrown by .NET with identical code.

Reproduced on versions: Unity 5.5.3f1, 5.5.4f1, 5.6.1p4, 2017.1.0b10, 2017.2.0a4