Steps to reproduce:
1. Open attached project "937501.zip"
2. Build 'main' scene for UWP
3. Open VS solution
4. Build & run on local machine
5. After launch observe VS output
*you can see that the string value is printed out in 'OnAfterDeserialize()'*
*right after 'OnStateEnter()' is called, however, the string value(which was printed out before) is null*
*in this case, integer member value remains the same, while string member value gets nulled*

Expected behavior: 'OnAfterDeserialize()' doesn't erase string member value on finish

Notes:
Not reproducible in Editor
Not reproducible with IL2CPP scripting backend

Reproducible with: 5.6.0b1, 5.6.3f1, 2017.1.0p3, 2017.2.0b5, 2017.3.0a2

Fixed in: 2017.3.0b8, 2018.1.0a3