Unity 2018 with .NET 4.X compatibility on AOT platforms crashes on fsMetaProperty.Read

[lakrsv]

Expected Behavior

When using FullSerializer on AOT platforms with the newest runtime & compatibility level, serialization/deserialization should complete successfully.

Current Behavior

With the newest runtime (.NET 4.X) with compatibility level .NET 4.X, serialization fails on AOT platforms (Android tested in my case).

I have traced the offending line down to "return ((PropertyInfo)_memberInfo).GetValue(context, new object[] { });" in fsMetaProperty.Read(object context)

Possible Solution

I worked around this issue for myself by changing the line
return ((PropertyInfo)_memberInfo).GetValue(context, new object[] { });
to
return ((PropertyInfo)_memberInfo).GetGetMethod().Invoke(context, null);

While this seems to resolve the issues, it causes the runtime tests to fail due to exceptions being thrown on that line. Due to this, I am currently using .NET Standard 2.0 without my work-around for now. (It may be possible to implement the hotfix in a compatible way by doing some kind of null-check prior)

Solution reference here:
https://forum.unity.com/threads/unity-5-0-3f2-il2cpp-problem-attempting-to-call-method-system-reflection-monoproperty-getteradapt.332335/page-2

Steps to Reproduce

1. Install Unity 2018.1.6f1
2. Build the FullSerializer.Testing.test_scene.unity with configuration specified in Context(Environment)
3. Watch it fail serialization

Context (Environment)

As Unity 2018 introduces many workflow improvements for us, I have upgraded our project to use it. I was experimenting with using the .NET 4.X compatibility level, but after hitting these issues I have decided to stay with .NET Standard 2.0 for now.

Unity Version: Unity 2018.1.6f1
FullSerializer Version (Latest commit): c01db30
Unity Target: Android 6.0, Huawei Mediapad T3
Scripting Runtime Version: .NET 4.x Equivalent
Scripting Backend: IL2CPP
Api Compatibility Level: .NET 4.x