Steps to repro:

1. Download attached project: https://drive.google.com/open?id=1MmcioZ-Z2MITlcrOLFFvc347lOhw3ra3
2. Open 'AdditiveLoading' scene;
3. Launch the scene;
4. In the Game view in scene's UI under 'Load' column press 'Gear' button to instantiate the Gear scene;

Expected result:
Scene 'Gear' is loaded.

Actual result:
Editor crashes. See attached video.

Last calls from the stacktrace:
0x00000001417A6389 (Unity) [c:\buildslave\unity\build\editor\src\gizmos\gizmomanager.cpp:198] GizmoManager::BuildGizmosFromGameObjectRecursive
0x00000001417A65C3 (Unity) [c:\buildslave\unity\build\editor\src\gizmos\gizmomanager.cpp:202] GizmoManager::BuildGizmosFromGameObjectRecursive
0x00000001417BCF82 (Unity) [c:\buildslave\unity\build\editor\src\gizmos\gizmomanager.cpp:211] GizmoManager::RecalculateGizmos
0x00000001417BD049 (Unity) [c:\buildslave\unity\build\editor\src\gizmos\gizmomanager.cpp:261] GizmoManager::RecalculateGizmosIfDirty
0x00000001417AD20B (Unity) [c:\buildslave\unity\build\editor\src\gizmos\gizmomanager.cpp:278] GizmoManager::DrawAllGizmos
0x00000001418C938E (Unity) [c:\buildslave\unity\build\editor\src\utility\editorcameradrawing.cpp:2759] Camera::FinishRenderingEditorCamera

Notes:
- Happens in 2018.3.0a4, 2018.2.0b11, 2018.1.6f1, 2017.4.6f1;
- Happens on Windows 10;
- Happens only in the current project; doesn't happen in the new project created from scratch;
- Happens only in Editor; Doesn't happen in Standalone player.