Invalid AABB inAABB error occurs on clearing reference resolution values for canvas scaler when scaler mode is set to scale with screen size

Steps to Repro:
1. Open attached project
2. Hierarchy > select canvas > canvas scaler > reference resolution value
3. Clear Y value for using backspace > Observe the error

Occurring with:
2018.1.0b4, 2017.3.0p2, 5.6.5p1, 5.6.4p3, 5.6.4p2, 5.6.4p1, 5.6.0f3,f2, 5.6.0a1

Note:
Didn't occur again when tried with new canvas

Environment:
Occurring on windows & Mac

Stack Trace:
Invalid AABB inAABB
UnityEngine.Canvas:SendWillRenderCanvases()