can't adjust creative breaking speed

Kelp, Coral, other ocean decorations don't generate in Caves buffet

Block entities in player's chunk become stuck when reloading the world

Light-emitting solid blocks (lit furnaces, magma blocks, glowstone, lit redstone ore) let light (sunlight, block light) through

Lilypads don't make sound when placed on water.

You can replace stuff (say, lava) by placing a lilypad on the side of a block, but you can't replace it by trying to place directly on the water.

Switching X sessions locks up the game.

Can't light TNT at y=255

Inconsistency in piston timing

Minecraft doesn't use a "player-per-chunk" based mob cap

Sneak doesn't display first-person bobbing

Placing a solid block near TNT and above redstone torch won't update the TNT