Steps to reprouce:

1. Download and import attached project. (LoadScene.zip)
2. Open scene: main.
3. Play.
4. Press UI Button.
5. Inspect console error messages

GetLocalizedString is not allowed to be called during serialization, call it from Awake or Start instead. Called from script 'TreeData' on game object 'Tree Data'.
See "Script Serialization" page in the Unity Manual for further details.

UnityException: GetLocalizedString is not allowed to be called during serialization, call it from Awake or Start instead. Called from script 'TreeData' on game object 'Tree Data'.
See "Script Serialization" page in the Unity Manual for further details.
TreeEditor.TreeGroupRoot..cctor ()
Rethrow as TypeInitializationException: An exception was thrown by the type initializer for TreeEditor.TreeGroupRoot

Notes: Error appears with both Application.LoadLevel and SceneManager.LoadScene. Also reproduces when scene is loaded by NetworkManager.

Reproduced on: 5.4.0b3, 5.3.2p1, 5.2.4f1, 5.1.4f1