Reproduction steps:
1. Open attached "Stripped" project.
2. Open "Scenes/Level_1-1" scene.
3. Expand "Canvas_Gameplay" game object in the Hierarchy.
4. Select "StageCleared" game object.
5. Remove "Canvas" component form it (RMB > Remove Component)"
6. Editor crashes on:

#0 0x000001015f6714 in GameObject::QueryComponentByType(Unity::Type const*) const
#1 0x000001028b6a44 in UI::Canvas::CalculateCanvasAlpha() const
#2 0x000001028b6988 in UI::Canvas::CalculateCanvasAlpha() const
#3 0x000001028b7a3c in UI::Canvas::UpdateBatches(bool)
#4 0x00000101fa263a in UI::InitializeCanvasManager()::UIEventsWillRenderCanvasesstruct::Forward()
#5 0x00000101ac786b in PlayerLoop()
#6 0x000001026330d5 in Application::UpdateScene(bool)
#7 0x0000010263009c in Application::UpdateSceneIfNeeded()
#8 0x0000010262f6ea in Application::TickTimer()
#9 0x007fff9d6badec in __NSFireTimer
#10 0x007fff8a571af4 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__

Regression introduced in: 5.5.0b3
Reproduced on: 5.5.0b3, 5.5.0p1, 5.6.0a6
Not reproducible on: 5.5.0b2