How to reproduce:
1. Load the project in 5.2.4f1, open and save the Game scene and close Unity
2. Open the project in 5.3.0f4
3. Delete NGUI folder
4. Import NGUI from Asset Store (3.9.6c, the latest)
5. Unity crashes with the error below "The file 'MemoryStream' is corrupted"
6. Reopen project and notice that Hierarchy is corrupted and doesn't show anything
7. Also it spams "NullReferenceException: Object reference not set to an instance of an object" error

Stacktrace is empty
Couldn't check if it is regression, because using this project asset store cannot be open with Unity 5.2