How to reproduce:
1. Open the user-supplied project
2. Make sure the scripting backend is set to IL2CPP and the API compatibility level is set to .NET Standard 2.0 in the Player Settings
3. Build and run the "SampleScene" Scene
4. Observe the crash

Reproducible with: 2018.4.13f1, 2019.2.12f1, 2019.3.0b10, 2020.1.0a13
Could not test with: 2017.4.34f1

Note: the Player crashes after being built on Unity versions 2018.4 through 2020.1. The Script throws a NullReferenceException when entering Play Mode in the Editor. In 2020.1, the NullReferenceException is not thrown in the Editor Console. Crash occurs on both .NET 4.x and .NET Standard 2.0. The build does not crash when the scripting backend is set to Mono. If GetIPv4Properties() is changed to GetIPv6Properties(), the build does not crash. Could not test on 2017.4 due to IL2CPP not being available.