Open chest in ocrean ruin/shipwreck cause lag

position and inventory(maybe all the playerdata) are not saved while a player open a save from the 1.12 version in 18w19a and 18w19b snapshot

summoned falling blocks could form a invisible border that slows down player's movement speed and make the sight shake

game crashing after loaded specific structure block in specific saves

showing nbt while signing on a book

Player appears standing after swimming in a 1x1 water

player is not getting stifle in a glass block

scoreboard command would disappear after save and quit to title, summon command would not be able to summon some entity such as lightning_bolt