I'm also encountering this issue. It specifically occurs when Unity tries to serialize a NetworkVariable<FixedString32Bytes>. I am able to set the value of the network variable and read it again ...

I have Unity 2017.2.0b5 (64-bit) and the latest Github for Unity release. Any additional information, configuration or data that might be necessary to reproduce the issue.

Ошибка в Unity NullReferenceException: Object reference not set to an instance of an object ...

We show you how to fix Object reference not set to an instance of an object error prompt which you may see in Microsoft Visual Studio.