Instantiating EventSystem in RuntimeInitializeLoadType.BeforeSceneLoad results in exception in windows build:
A script behaviour has a different serialization layout when loading. (Read 32 bytes but expected 96 bytes)
Did you #ifdef UNITY_EDITOR a section of your serialized properties in any of your scripts?

Steps to reproduce:
1. Open provided example project
2. Open Assets/Scene.unity
3. Press Play, notice no error is displayed
4. Press File > Build & Run and build a Windows player
5. Run the built player
6. Notice the exceptions

Reproduced on Windows 10 x64 with 5.2.0f2 (d7f8e5b3cbb5b, 5.3.0b1 (a535853f4e7c)