Elder Guardian hard crashes the game when it dies.

Partner Rank: 1

Verification builds: 1.16.100.53
Regression builds: 1.16.20

Summary: Elder Guardian hard crashes the game when it dies. Infinity Dungeon EX uses this mob for its final boss.

Impact: Hard crashing is extremely bad for maps, it rolls back game content and breaks game logic. In addition, this is a popular realms+ map. It makes them unable to be completed and causes negative reaction to players. Moreover we have no way of knowing why it crashes and so cannot fix it on our end.

Repro Steps:

1. Start a vanilla game
2. Do /summon elder_guardian
3. give yourself a diamond sword or something to kill it faster like some instant damage arrows
4. kill the thing

Expected Results: The game should not crash

Observed Results: The game hard crashes without any asserts

Screenshots/Videos attached: No, it would be a video of it straight up crashing so would not be helpful.