To reproduce:
1. Open project
2. Select Canvas gameObject
3. Open animation window
4. Play 'OldAnim' and 'NewAnim'

Expected: both clips will look identical
Actual: 'OldAnim' is broken, 'Could not register property modification for animation binding m_AnchoredPosition.z of object Image, modifications will not be automatically reverted' warnings are thrown

Reproduced on: 2017.2.1p3, 2017.3.1p1, 2018.1.0b6, 2018.2.0a1

Note: 'OldAnim' is created on 2017.1