Minecraft 1.21 snapshot 24w21a patch notes: Reverted piston sound changes, new gamerule, trial chamber generation changes, and more

As the launch date of Minecraft's major Tricky Trials update fast approaches, Mojang has consistently been releasing new test versions, some of which focus on bug fixes and minor changes. The Minecraft 1.21 snapshot 24w21a effectively improves overall smoothness and prevents crashes. The main highlights of this Java Edition snapshot include some minor sound changes to the piston and a few improvements to this title's multiplayer experience.

This article will cover the detailed release notes for the 1.21 snapshot 24w21a update for Minecraft's Java Edition.

Minecraft 1.21 snapshot 24w21a: Everything you need to know

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Main changes

The piston sound has been reverted to the previous one. Here are all the main changes in this snapshot:

It seems we cooked a bit too hard with the new Piston sounds last week, which is why we're reverting back to the old sounds again
Lowered volume of original sounds to address initial feedback of Pistons being too loud
Pause menu now can include a list of links provided by server
Improvements to the disconnection screen
Any member of a Realm can now upgrade a world
In the Realms main screen, all online players of a Realm are displayed
When hovered, a tooltip is shown with each player's head and name

Vaults

The vaults in Minecraft 1.21 have received a quality of life change:

Added sound effect to help players understand they've already looted a vault

Trial chambers

A minor change has been made to the spawn location of the new trial chambers:

Trial Chambers are less likely to generate in the Deep Dark

Animal panic

Animal mobs in Minecraft will now panic based on the sustained damage. Here's everything we know:

Animals now panic based on the damage caused by predefined Damage Source Types
The panic lasts for 2 seconds after the damage is dealt. The following damage type tags are used by vanilla animals:
panic_environmental_causes: Used by Wolves, Polar Bears (adults) and Pandas
panic_causes: Used by all other animals and baby Polar Bears

Server links

Servers can now provide a list of links to clients
If client has received any links, a new button called "Server Links..." will show up in pause game screen
To make space for that button, "Report Bugs" and "Give Feedback" buttons might be moved into a sub-screen if necessary

Disconnection screen improvements

In some cases client will now store detailed information about disconnection (similar to crash reports)
When that happens, new "Open Disconnection Report Directory" button will be added to the disconnection screen
When server provides link for bug reporting, it will be also be added as a button to the disconnection screen

FIXED BUGS IN 24W21A

A couple of major bugs, including a six-year-old one, have been fixed in this Minecraft update. Here's a detailed list of the fixed issues:

MC-67 - Entities with passengers cannot travel through portals
MC-31819 - Hunger saturation depletes on peaceful difficulty
MC-116279 - Non-player entities going through Nether portal do not generate portal in Nether if none exists
MC-151648 - Non-player entities cannot travel through unlinked nether portals
MC-170103 - Untamed wolves only beg for food while being angry and jumping
MC-260346 - Custom music discs cut off when vanilla disc would normally end
MC-266290 - Double doors do not automatically form between waxed and unwaxed copper doors, even of the same variant
MC-266586 - Trial chambers can spawn directly inside the deep dark biome
MC-266626 - Breeze doesn't stop attacking the player when it enters on the same team
MC-267967 - Breezes ignore the deflects_projectiles entity type tag
MC-268438 - Baby armadillos can still eat while rolled up
MC-269034 - Wolves no longer teleport while trying to pathfind out of Lava
MC-269351 - The Bolt Armor Trim cannot be duplicated with Waxed Copper Block
MC-269370 - Sharp lag spike caused by incorrect upper limit on particles created by mace smash attack
MC-269460 - Thorns enchantment doesn't work when entities are hit by wind charges
MC-269964 - Ominous item spawners are missing an NBT load for spawn_item_after_ticks
MC-269988 - New potion effects don't apply their respective behaviors when creeper explodes
MC-270024 - When drinking ominous bottles, bad omen of higher levels can be overriden by lower amplifiers
MC-270377 - Wind charges can be hit and redirected the moment they are thrown
MC-270573 - Mounted entities are immune to wind charge damage
MC-270808 - Any item in the armor.body slot protects wolves from taking damage
MC-271458 - Channeling tridents no longer summon lightning bolt every time hitting lightning rod under thunderstorm
MC-271573 - Attribute Enchantments Don't Behave Properly on Armor
MC-271634 - Custom enchantments don't appear in the creative menu
MC-271718 - Crash when randomized_int_state_provider is applied to blocks lacking the property
MC-271753 - Crash due to overflow inside cost calculation in by_cost_with_difficulty
MC-271856 - Crossbows enchanted with Quick Charge do not benefit from its effects when used in the offhand
MC-271868 - Frost walker replaces flowing water now
MC-271901 - Entity effect "play_sound" Field "pitch" value upper limit is 1.0 instead of 2.0
MC-271911 - Frost walker no longer works with void or cave air
MC-271914 - Soul speed enchantment doesn't emit particles when the entity is controlled by a player
MC-272039 - Soul Speed uses durability in creative mode
MC-272042 - If players have max health over 20 and die, when they respawn they will have 20 health instead of their max health
MC-272043 - The game crashes when entities die while having the oozing effect
MC-272075 - Attempting to step up while controlling entity and moving fast often glitches
MC-272084 - Creepers with potion effects no longer create area effect clouds upon exploding
MC-272182 - Knowledge Books no longer function properly with a stack size of 1 in survival/adventure mode

That's all the notes on the bug fixes and changes. If you're interested, you can visit the link to the official Minecraft webpage embedded in the tweet provided earlier to learn about the technical changes made in this snapshot.