I think it is related to MC-65587? But not quite, since it's a full on crash, which I will also be adding as an attached file.
crash-2021-04-11_01.31.38-client.txt

I'm not sure how they are created, but certain players are able to give themselves crash heads using a hacked client in creative and crash everyone around them. It's not a small crash either, the whole game instantly closes. I would be very happy to see this fixed.