Reproduction steps

1) Checkout HDRP/staging github branch
2) Edit manifest to use mentioned branch(replace all local paths).
3) Open project (its just an empty one using HDRP staging)
4) Delete everything in the scene (optional)
5) Add Camera
6) Add Raytracing environment
7) Add Area light
8) Minimize Unity (also clicking around aimlessly is an alternative)
9) Maximize Unity
10) Delete area light
11) Unity crashes

Additional notes:
In the video you can see more steps taken. But its all just to showcase that if one of these 3 elements is missing, Unity will not crash (Camera, Rtx env, minimization or random clicking). This was also reproduced with normal project with way more gameobjects, I tried to reduce it to bare minimum.

Specs:
RTX 2070 card, HDRP/staging branch, Version 2020.1.0a2 (d7a2c5ce73c0)