To reproduce:
1. Open attached project "case_1069270-letter-game 2.zip"
2. Build for iOS
3. Deploy the built project to an iOS device through Xcode
4. Press button in the bottom right
5. Select any of the white cubes in the middle of the screen
6. Press the red button on the top left two times

Expected result: the scene that was opened before is opened
Actual result: app crashes

Reproduced on:
2018.2.0b8 2018.2.3f1

Not reproduced on:
2018.2.0b7 2018.3.0a8

Device reproduced on:
iPhone 7 iOS 11.0

Crash log:
frame #0: 0x00000001024fcdac lettergameoptimized`::WillDestroyGameObject() at GameObject.cpp:93 [opt]
frame #1: 0x00000001027f4c58 lettergameoptimized`::PreDestroyRecursive() at GameObjectUtility.cpp:1449 [opt]
frame #2: 0x00000001027f4e20 lettergameoptimized`::DestroyGameObjectHierarchy() at GameObjectUtility.cpp:1516 [opt]
frame #3: 0x00000001027f546c lettergameoptimized`::DestroyObjectHighLevel() at GameObjectUtility.cpp:1676 [opt]
frame #4: 0x00000001028118a0 lettergameoptimized`::UnloadGameScene() at SceneUnloading.cpp:41 [opt]
frame #5: 0x0000000102827d38 lettergameoptimized`::PlayerLoadSceneFromThread() at LoadSceneOperation.cpp:521