Minecraft: Java Edition ยท Patch release

Minecraft 1.21.1

1.21.1 is a hotfix for Tricky Trials that closed a remote server crash and a block entity duplication exploit. It keeps protocol 767, so it is compatible with 1.21 servers.

Released
Server needs
Java 21
Protocol
767
Start a 1.21.1 serverStart a free server

Seven days free, no card. Pick 1.21.1 when you create the server, or switch an existing one from the panel.

A patch of

Minecraft 1.21 Tricky Trials

Tricky Trials added trial chambers, an underground structure built around trial spawners and vaults.

Everything 1.21 added

What changed in Minecraft 1.21.1

The fixes and changes of this release.

  • Fixed a server crash from malicious command completion requests
  • Fixed a block entity swap exploit using update suppression
  • Compatible with 1.21 servers
  • Tzotzil and Belarusian Latin languages added
  • Fixed the crossbow arm spinning while swimming

Blocks and items

  • Fixed a block entity swap exploit that used update suppression

Mobs

  • Fixed the cat interaction trigger for player_interacted_with_entity

Gameplay

  • Crossbow arm no longer spins while swimming
  • Tzotzil and Belarusian Latin languages added

Running a Minecraft 1.21.1 server

What the release means for whoever runs the server.

  • Requires Java SE 21
  • Protocol version 767
  • Data pack format 48
  • Compatible with 1.21 servers
  • Fixes a stack exhaustion crash from malicious command completion requests
  • Every 1.21 server should be on this version instead

Before you update a world: take a backup. A world opened in 1.21.1 cannot be opened in an older version again. How backups work here.

1.21.1 on FadeHost

The right Java, set for you
A 1.21.1 server needs Java 21, and the panel starts it with a Java that fits. Nothing to install, nothing to pick.
Server software for 1.21.1
PaperPurpurVanillaFabricForgeNeoForgeMohist
Who can join
Players on 1.21.1 and on 1.21: the network protocol is the same.
Start a 1.21.1 server

Questions about 1.21.1

When was Minecraft 1.21.1 released?

Minecraft: Java Edition 1.21.1 was released on August 8, 2024.

What Java version does a Minecraft 1.21.1 server need?

Java 21. On FadeHost the server starts with the right Java for its Minecraft version on its own, so there is nothing to install or switch.

What did Minecraft 1.21.1 change?

1.21.1 is a hotfix for Tricky Trials that closed a remote server crash and a block entity duplication exploit. It keeps protocol 767, so it is compatible with 1.21 servers.

Can players on another version join a 1.21.1 server?

Players on 1.21 can: the network protocol (767) is the same. Any other version has to match the server, unless a Paper server runs plugins such as ViaVersion and ViaBackwards.

Can I update my world to Minecraft 1.21.1?

Yes. Take a backup, switch the server to 1.21.1 and start it: the world is converted on the first boot. A world opened in 1.21.1 cannot be opened in an older version again, so keep the backup until you are sure.

How do I start a Minecraft 1.21.1 server?

Create a server on FadeHost and pick 1.21.1 in the software list: Paper, Purpur, Vanilla, Fabric, Forge, NeoForge and Mohist are there for this version. It is online in about a minute. The free tier runs a 2 GB server at no cost, and a paid server is sized to the RAM you need.

The release before

Minecraft 1.21 Tricky Trials

June 13, 2024

The release after

Minecraft 1.21.2 Bundles of Bravery

October 22, 2024

Read on

Change a server's version

Version, software and loader build are one setting in the panel.

Java version errors

What the wrong Java looks like in the console, and why it does not happen here.

RAM calculator

How much memory a server needs, sized from servers measured on our nodes.

Every Minecraft version

All releases, what each one added and the Java it needs.

Release facts from the Minecraft Wiki:Java Edition 1.21.1. Minecraft is a trademark of Mojang; FadeHost is not affiliated with Mojang or Microsoft.