Possible Fixes

Yes

Modpack Version

2.25

What happened?

Ice Breaker relic has Earthquake ability, it is when you jump on mob, press the skill mid-air and player falls down and hits everyone around with AOE.
So if you executed the skill being high enough to kill the mob in 1 hit - the mob health drops to zero, but it doesnt die and you cannot kill it anymore, even with "kill" command. It happens due to Earthquake ability removes Health and AbsorptionAmount from NBT completely:

Temporary solution is to look at glitched entity to capture the UUID and enter these commands:
/data modify entity UUID Health set value 1.0
/data modify entity UUID AbsorptionAmount set value 0.0

This situation creates second bug - if you hit such glitched mob with a sword enchanted with "Life Stealing" - your health will vanish too (because it tries math on non-existing variables), you cannot move, your camera will start shaking and you cannot open the inventory. You can fly though(with endgame armors) and can use tools on your belt.
Solution to remove all glitch effects:
/heal

latest.log

No response

Developer reports

No response