Reset functionality not working for Animation and Animation clip

Steps to Repro:
1. Create or Open attached project > project window > right click
2. Animation > select animation clip > change few properties
3. Click cogwheel icon > reset > observe that the properties are not getting reset to default
4. Hierarchy window > right click > empty game object
5. Add component > animation > change few properties
6. Click cogwheel icon > reset > observe that the properties are not getting reset to default

Expected Result:
Component properties should reset to the default values

Occurring with:
2018.1.0b5, 2017.3.0p4, 2017.2.1p2, 2017.1.3f1, 5.6.5p1

Environment:
Occurring on Windows and Mac

Note:
Following error occurs when resetting animation clip on Unity 5.6.5p1

Assertion failed on expression: 'MecanimDataWasBuilt()'
UnityEditor.DockArea:OnGUI()