Perhaps disregarded
Attached crash report
Confirmed for 17w13b
I think this is the effect of BUD pistons because since BUDs don't realize that they are powered until a block update is performed, the BUD will be stuck in its current position, if it was powered it will remain like that and since in the video presented does not place a block beside the piston and a block near it is powered, it won't realized its powered state.
"Reduces all damage, except damage from the Void, the /kill command, or hunger damage" the full description of protection, so protection also reduces drowning dmg.
I think this is connected to the translocation piston bug, because when pistons extend, they become air for a short while, making other blocks pop out, which is also what translocation pistons do to move entities 😞
@Alexander
Primed TNT and Armor Stands are non-collidable entities, same with item frames
Work as Intended? So does this mean the world border is a solid block that spiders can climb? Also, the world border is transparent and can be phased through, meaning this cannot qualify the world border as solid and spiders can't climp on non-solid blocks (atleast in my experience)
"If multiple items have the enchantment, one will be chosen at random for each XP orb collected, and if the chosen item does not need repair, the XP will be added to the player's total as normal, rather than choosing another item to repair."
Guardians deal magic damage as well as witches, maybe the thorns enchantment only works if the damage source is physical not magical
On what i think is that, since thorns only deals 1-4 damage when its triggered (thorns have a percentage of when it will trigger and it increases in each level but for those levels more than 10 it will be: (level-10)=thorn dmg) and since witches have 80% magic resistance plus thorns cannot be considered as physical damage, 1-4 thorns damage will only deal 0.15-0.5 damage to the witch, in which, that number is less than 1 (half a heart) so it might not be registered as a damage value and then ignored
Respiration increases the visibility of the player in water by 25% (not sure) per level, any other levels more than 3 will extremely brighten water visibility since it exceeds 100%, respiration X will give you 250% more visibility (level x 25%), making it very bright
(Minecraftwiki - Enchanting)
Perhaps the fortress needs to be loaded first in 1.12 and then re-load it in 1,16.3?