How to reproduce:
1. Download and open the project from the given link in the edit field
2. In the Project window go to the "Assets>Models" then find and add "unitychan" model to the scene
3. Select unitychan GameObject in the Hierarchy
4. Go to "Window>Animations" and create a new animation
5. In Animation window press on the red circle to start recording animation

Expected result: when pressing record animation on unitychan model stays still
Actual result: when pressing record animation on unitychan model folds and changes position

Reproducible with: 2017.4.9f1, 2018.1.9f1, 2018.2.3f1
Not reproducible with: 2018.3.0a9 (Could not add model to the Scene)

Note: this issue was found with Unitychan, but it seems to occur with othe models as well