Reproduction steps:
1. Open the attached project ("1228823.zip")
2. Select "MOB1_Crouch_Idle_V2.fbx" model in Assets
3. Press the arrow on the side to see the contents of the model
4. Select the animation clip of the model while Inspector is open to display the animation clips properties

Reproducible with: 2017.4.38f1, 2018.4.19f1, 2019.3.6f1, 2020.1.0b2, 2020.2.0a4

First lines of the stacktrace:
0x00007FF68F132FD9 (Unity) UnityEngine::Animation::SetBoundCurveFloatValue
0x00007FF68F1472C3 (Unity) AnimationBinder::SetFloatValue
0x00007FF68F196FA0 (Unity) SampleAnimation
0x00007FF68F702A29 (Unity) AnimationClip_CUSTOM_SampleAnimation

Notes:
- The issue seems to reproduce only when using the Default layout
- The AnimationClips seem to react this way only when the Animation Type on the model Rig is set to Legacy
- When the model has a corrupted AnimationClip, attempting to change the tab in Inspector to Animation will trigger the crash as well. After this, the crash will reproduce every time the model is selected as it will try to display the Animation tab right away
- If Inspector is not displayed, the crash doesn't reproduce