Minecraft Wiki
Minecraft 21w20a
Java Edition 21w20a.png

Java Edition



Release date

May 19, 2021

Snapshot for



Client (.json)
Data pack[note 1]

Obfuscation maps


Protocol version

 dec: 1073741852
 hex: 4000001C

Data version


21w20a[1] is the twenty-second and final snapshot for Java Edition 1.17, released on May 19, 2021, which makes tweaks and fixes bugs, most of which relate to axolotl behavior and world generation issues.



  • Added HasVisualFire NBT tag.
    • Entities with this tag visually appear on fire, even if they are not actually on fire.



Glow Lichen
  • Now drops the correct amount of glow lichen if there's multiple in one block space.
Rooted Dirt
Structure block
  • All invisible blocks are now displayed as small cubes by save mode structure blocks; previously barriers and light blocks would not display at all.[3][4]
    • Variants of air still all appear identical and are not distinguished.[5]
Air, Cave Air and Void Air Structure Void Barrier Light
Before Air (shown) JE2.png Structure Void (shown) JE2.png Blank.png Blank.png
After Air (shown) JE2.png Structure Void (shown) JE3.png Barrier (shown) JE1.png Light (shown) JE1.png


Big Dripleaf
  • Tweaked the big dripleaf's inventory model.
Light Block
  • Changed the textures of the light block's inventory icons to prevent overlap with the stack number.


  • Axolotls will now only play dead when in water.
  • Can no longer be fed tropical fish, only buckets of tropical fish, as axolotls in real life eat live fish. This also brings it to parity with Bedrock Edition.[6]
  • When fed with a bucket of tropical fish, it will return a water bucket instead of a bucket.
  • Llamas no longer spit at players in peaceful mode.

World generation[]

Amethyst Geodes
  • Geodes were made rarer.


Distance effects
  • Fixed a precision loss issue with minecraft:location_check.[7]
  • GUI narration now includes position and usage of hovered or focused element.
  • Added the cave_vines_plant block to the bee_growables block tag.
    • The cave_vines block was already in this tag.
  • Removed the tropical fish item from the axolotl_tempt_items item tag.
  • Changed the strings "Chat disabled by launcher option, cannot send message" and "Chat not allowed by account settings, cannot send message" to "Chat disabled by launcher option. Cannot send message" and "Chat not allowed by account settings. Cannot send message", respectively.
  • While connecting to a server, the client will send a handshake packet with "hostname" and "port" field directly padded with address given in address text field directly, instead of converting them to the real hostname and port.


77 issues fixed
From released versions before 1.17
From the 1.17 development versions
  • MC-203712Amethyst Geodes cause floating water/lava to generate when intersecting water/lava caves/pools.
  • MC-203867 – Amethyst geodes can overwrite bedrock.
  • MC-204393Lava Cauldron emits redstone signal strength 1 instead of 3.
  • MC-204902Dirt paths are no longer compatible with the programmer art resource pack.
  • MC-205104 – Rideable mobs are not affected by powder snow's freezing effect while being ridden.
  • MC-205120 – Freezing hearts aren't displayed properly in Programmer Art resource pack.
  • MC-205250 – Amethyst geodes can generate in a stronghold and can potentially destroy the end portal frames.
  • MC-205680minecraft:location_check predicate floating point imprecision.
  • MC-206107Parrots sitting on shoulders do not freeze in powder snow.
  • MC-206131Amethyst blocks are transparent / don't conduct Redstone.
  • MC-206601 – Potion particles are showing when looking through spyglass.
  • MC-206839Pointed dripstones cause extreme durability damage to helmets.
  • MC-207366 – Trying to modify the world height of a world after it's already been generated gives a null pointer exception.
  • MC-208586 – Axolotls get stuck and spin constantly on top of lily pads.
  • MC-208589 – Axolotls have a swimming animation (move their body up- and downwards) when on land.
  • MC-208617 – Axolotls sometimes twitch rapidly when adjusting their rotation.
  • MC-208624 – An axolotl is not correctly centered whilst inside of a boat.
  • MC-208641 – Axolotl movement glitch on stairs.
  • MC-208649 – Breeding axolotl with a bucket of tropical gives back a bucket instead of a water bucket.
  • MC-208654 – Collecting an axolotl with a water bucket in creative mode replaces the original bucket.
  • MC-208675Axolotls sometimes use walking animation when in shallow water.
  • MC-208682 – Axolotls frequently get stuck inside of waterlogged blocks.
  • MC-208691 – Axolotls play dead even when they take damage without being attacked by an entity.
  • MC-208735 – Axolotls attempt to pathfind towards unreachable water, then start spinning, eventually drying out and dying.
  • MC-209324Pointed Dripstone can be broken with tridents in spawn protection.
  • MC-212125 – Only one glow lichen drops when using shears on multiple in a single block space.
  • MC-212531Shulkers can rotate their heads up and down.
  • MC-212931 – Fire extinguishing sound doesn't play when mobs are extinguished with rain/water.
  • MC-214041Mob can't properly or difficult walk on big dripleaf, when the big dripleaf is 4 blocks or more from the ground.
  • MC-214909 – Top half of a small dripleaf can turn into a ghost block when placing it in water while the water is being removed.
  • MC-215665 – Amethyst Geodes can overlap with dungeons.
  • MC-216214netherrack_replace_blobs with water as target crashes the game.
  • MC-216980 – Comma splices in two source strings (EN_US).
  • MC-217113Foxes spawned inside of powder snow sleeps.
  • MC-217608 – The big dripleaf texture is not vertically centered.
  • MC-217610 – Too much of the big dripleaf is hidden when placed inside of an item frame.
  • MC-217742Campfires and TNT can be lit by players using arrows shot from flame bows in spawn protection.
  • MC-219856 – F3 + L isn't sorted alphabetically in the debug screen.
  • MC-219870 – The Mojang loading screen upon start up flashes black.
  • MC-220063Sweet berries and glow berries sound events are named extremely differently.
  • MC-220128 – Parity Issue: Rooted dirt won't turn into the dirt and drop roots item after tilling with hoe in Java.
  • MC-220867Fossils can generate through bedrock.
  • MC-221566 – Name color for light is incorrect.
  • MC-221833 – Light blocks are not shown within structure block bounds with Show Invisible Blocks on.
  • MC-221863Powder Snow can be broken by players on fire in spawn protection.
  • MC-221984 – Collecting an axolotl in a bucket and then placing it resets its kill cooldown.
  • MC-222002 – Light item displays the wrong level number.
  • MC-222116 – Splash water bottles doesn't extinguish candle cakes.
  • MC-222797Axolotl can be bred with just tropical fish items, not just bucket ones.
  • MC-223371Powder snow can be destroyed through the use of a flame bow in spawn protection.
  • MC-223372 – You can decrease the level of a water or powder snow cauldron, through the use of an entity on fire in spawn protection.
  • MC-224320minecraft.used:minecraft.potion doesn't increase when filling a partially filled cauldron with a water bottle.
  • MC-224322 – Powder snow can create ghost blocks in creative mode.
  • MC-224480 – Powder snow doesn't melt into water in cauldrons.
  • MC-224482 – Superflat presets no longer generate with decorations.
  • MC-225078 – Upgrading from 1.12.2 and below will cause items to lose enchantments.
  • MC-225253Dying in a nether portal softlocks the player on the "You Died!" menu.
From the previous development version
  • MC-225347cave_vines_plant isn't in #bee_growables.
  • MC-225352 – Geodes have not been made "significantly rarer".
Private issues
  • MC-225360 – Cannot resolve SRV records: unknown host.



Videos made by slicedlime:


  1. "Minecraft Snapshot 21w20a" – Minecraft.net, May 19, 2021
  2. MC-220128
  3. MC-102220
  4. MC-221833
  5. MC-221834
  6. MCPE-123573 – resolved as "Works As Intended"
  7. MC-205680


  1. Re-enables features set to release for 1.18.