How to reproduce:
1. Open the attached project "case_1143420-TimelineAnimationIssueStripped_2" and scene "Test"
2. Select the "ParentWithTimeline" GameObject to view its Timeline
3. Hit the Play button in the Timeline Window and observe the Scene View

Expected result: a fighting animation is played on the GameObject linked to by the animation track
Actual result: the character's model is mangled when playing the animation (looks like a bone mismatch or a skinning issue)

Reproducible with: 2017.4.26f1, 2018.3.13f1, 2019.1.0f2, 2019.2.0a12

Note: the GameObject with the Animator referenced by the animation track has a hierarchy from a previous version of the animation's FBX file. Creating a new instance of the played animation's FBX asset in the Scene and referencing it from the Timeline plays the animation correctly. However, both the old and the new GameObjects reference the same model and avatar and only have a slightly different Transform hierarchy (the bulk of the bones going from the root seem to have identical positions and paths in the bone hierarchy)