Mostly just one important fix, otherwise relevant for ViaBackwards

• Fixed regression in disguised chat handling in 1.20.3->1.20.5
• Fixed missing chunk_biomes conversion in 1.21.4->1.21.5 (by Gerrygames)
• Partially fixed picking blocks for 1.21.4+ clients on legacy servers (by Pablete1234)

Please also note that at some point in the future, ViaVersion will require at least Java 21 to run. If you're already on 17, an update should be trivial.

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

1.21.5 client support

• Fixed custom model data handling in block entities in 1.21.2->1.21.4
• Fixed removed item data components in item hover events in 1.21->1.21.2 and 1.21.2->1.21.4
• Fixed shulker boxes content not being visible in 1.20.3->1.20.5 (by EnZaXD)
• Fixes to item hover event handling in 1.20.3->1.20.5 (by kennytv, EnZaXD)
• Fixed duplicate registry entries causing errors (by EnZaXD)
• Fixed blocks in minecarts in 1.8->1.9 (by EnZaXD)
• Fixed error with 1.9+ clients joining a 1.8 server when ViaVersion installed on Velocity (by EnZaXD)
• Removed consumable blocking sound for 1.21.4 clients on 1.8 servers (by lowercasebtw)

This version also adds custom payload sending to get player protocol version data across platforms (by EnZaXD). If ViaVersion is installed on a proxy (e.g. Velocity or ViaProxy) or the client (e.g. ViaFabricPlus), you may be able to get this information by listening to custom payloads ("plugin messages") on any platform within the chain, which can be useful for anti-cheats and other player version-dependent code. See the wiki for more information. Example JSON data:

{
  "platformName": "Velocity",
  "platformVersion": "3.1.2",
  "version": 760,
  "versionName": "1.19.4"
}

Please also note that at some point in the future, ViaVersion will require at least Java 21 to run. If you're already on 17, an update should be trivial.

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

• Various fixes to block pick handling on Paper servers in 1.21.2->1.21.4 (by riku6460 and booky10)
• Fixed error when dropping custom painting on the ground in 1.21.2->1.21.4
• Fixed transfer intent in handshake in 1.20.4->1.20.5 (by RK_01)
• Handle legacy show_entity text component format in newer protocols (by EnZaXD)
• The modern shield blocking fix on 1.8 servers only applies to 1.21.4+ clients now due to inconsistencies before that; removed sword-blocking-via-consumable config option to always be enabled (by roccodev)
• Send op permission level 4 for use of command blocks in 1.8->1.9 (by EnZaXD)
• Ignore bad entity packets below 1.14 as per Vanilla handling (by EnZaXD)

1.21.4 client support and mostly config-related changes and fixes to older server versions!
Important note: Please make sure to update your Java version to Java 21+, as ViaVersion will require it in a future release!

• Greatly reduced netty byte buf (memory) allocation
• The sword-blocking emulation for 1.20.5+ clients on 1.8 servers can now be disabled via sword-blocking-via-consumable (by EnZaXD)
• The fix-1_21-placement-rotation config option is now enabled by default (by Pro4D)
• Fixed reading of equippable (by DavyCraft648)
• Fixed reading of armor trim override materials
• Fixed regression in tag sending for 1.20.2 to 1.20.4 clients on older servers
• Fixed recipe book recipe ingredients for newer clients on 1.12 servers and older (by valaphee)
• Fixed block action block id handling across multiple protocols (by valaphee)
• Fixed 1.12->1.13 block connections on snowy grass, mycelium and podzol (by lowercasebtw)
• Fixed dropped items being invisible until entity data is sent in 1.10->1.11 (by EnZaXD)
• Improved 1.21 client enchantment handling on legacy servers (by Pablete1234)
• Fixed fix-1_21-placement-rotation not working after changing its value and running /viaversion reload (by EnZaXD)
• Fixed fix-1_21-placement-rotation causing some issues with with anti-cheats (by EnZaXD)

Additional notes:

• Custom model data no longer exists in its previous form. If you can, use the item_model data component, else make sure your resource pack is updated to use the new custom model data format and its first range_dispatch float
• Picking blocks will not work for 1.21.4 clients on servers older than about 1.12. Picking entities does not work on servers older than 1.20.4. Both are Paper specific platform fixes and require certain API to be present

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

Lots of fixes, mostly to edge case data handling, and some more to older versions!

• Fixed items with block predicates causing disconnects for creative mode clients in 1.21->1.21.2 (by EnZaXD)
• Fixed errors from level 0 enchantments in 1.21->1.21.2
• Fixed painting entity data in 1.21->1.21.2
• Fixed opening chest boat inventories causing disconnects in 1.21->1.21.2
• Fixed boat types in 1.21->1.21.2 (by EnZaXD)
• Fixed item_name<->default name priority for items in 1.21->1.21.2 (by EnZaXD)
• Fixed some issues with item hover event displays in 1.20.5 and 1.21.2 (by EnZaXD)
• Fixed handling of empty lock codes in 1.21->1.21.2, usually sent by older servers (by valaphee, EnZaXD, kennytv)
• Fixed possible anticheat issues by dropping idle packets where only horizontal collision changed in 1.21->1.21.2 (by EnZaXD)
• Fixed empty custom data tags sometimes being removed with creative clients on 1.20.5/1.21 (by EnZaXD)
• Send enabled features packet in config phase for clients that have it in 1.19.1->1.19.3 (by EnZaXD)
• Fixed handling of block entity custom names in 1.12->1.13 (by EnZaXD)
• Fixed chunks possibly being invisible on 1.8 servers and older (by RK_01)
• Fixed some edgecase area effect cloud particle errors on older servers
• 1.21.2+ clients on 1.8 servers now get proper sword blocking animations through consumable item data (by RK_01)

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

1.21.2 client support

• Fixed a possible crash on older servers (thanks to EnZaXD)
• Note that disabling strict-error-handling no longer has any effect on 1.21.2+ clients, affected errors include:
  • scoreboard related plugins that remove players from invalid teams, or try to add players to duplicate teams.
  • enchantment related plugins registering their custom enchantments/other registry entries multiple times.
• Known issue: Boats visually lose their wood type for 1.21.2+ clients. The fix for this is a bit more complicated and has been postponed to the next release.

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

• Fixed a regression from 5.0.4 where tags weren't updated correctly

5.0.4 Changelog:

On top of a few smaller fixes, this update also comes with various small performance and memory allocation optimizations

• Added hide-scoreboard-numbers config option to hide scoreboard score numbers in 1.20.2->1.20.3 (by Pablete1234)
• Added fix-1_21-placement-rotation config option to fix slightly behind block placement rotation when turning quickly in 1.20.5->1.21. Disabled by default as it may trigger anticheats (by EnZaXD)
• Fixed sound id rewriting in custom item instrument and jukebox data in 1.20.5->1.21
• Fixed bad conversion of can place on/can break in item hover events in 1.20.3->1.20.5 (by EnZaXD)
• Fixed possible errors with entity equipment in 1.20.3->1.20.5 (by EnZaXD)
• Added missing written book component handling in newer protocols for nested item data (by EnZaXD)
• Re-added "Invalid book tag" view in 1.20.4->1.20.5 (by EnZaXD)
• Fixed bossbar issues in 1.8->1.9 (by EnZaXD)
• Improved 1.8->1.9 sound mappings (by RK_01)
• Fixed handling of various non-standard data across protocols (by EnZaXD)

If you want to get larger version updates early, including 1.21.2, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

On top of a few smaller fixes, this update also comes with various small performance and memory allocation optimizations

• Added hide-scoreboard-numbers config option to hide scoreboard score numbers in 1.20.2->1.20.3 (by Pablete1234)
• Added fix-1_21-placement-rotation config option to fix slightly behind block placement rotation when turning quickly in 1.20.5->1.21. Disabled by default as it may trigger anticheats (by EnZaXD)
• Fixed sound id rewriting in custom item instrument and jukebox data in 1.20.5->1.21
• Fixed bad conversion of can place on/can break in item hover events in 1.20.3->1.20.5 (by EnZaXD)
• Fixed possible errors with entity equipment in 1.20.3->1.20.5 (by EnZaXD)
• Added missing written book component handling in newer protocols for nested item data (by EnZaXD)
• Re-added "Invalid book tag" view in 1.20.4->1.20.5 (by EnZaXD)
• Fixed bossbar issues in 1.8->1.9 (by EnZaXD)
• Improved 1.8->1.9 sound mappings (by RK_01)
• Fixed handling of various non-standard data across protocols (by EnZaXD)

If you want to get larger version updates early, including 1.21.2, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

• Partially fixed 1.20.5->1.21 enchantment handling on older/non-Paper servers (by EnZaXD)
• Fixed fast switching armor cancelling sprinting in 1.20.5->1.21
• Fixed handling of custom armor trim patterns and materials in 1.20.3->1.20.5
• Fixed erronous area effect cloud particle handling in 1.20.2->1.20.3
• Fixed an edge case with custom item frame rotation handling in 1.16.4->1.17 (by EnZaXD)

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.

• Fixed horse and llama inventory issues in 1.20.5->1.21 (by EnZaXD)
• Fixed issues with attributes in 1.20.5->1.21 (by kennytv and EnZaXD)
• Fixed possible kicks from out-of-order-chat in 1.20.3->1.20.5 (by Gegy)
• Fixed shulker box tooltips in 1.20.3->1.20.5 (by EnZaXD)
• Fixed filtered book page handling in 1.20.2->1.20.3 (by EnZaXD)
• "Message not delivered" messages no longer appear in 1.20->1.20.2
• Improved the 1.20.3 crossbow max damage and 1.8 sword blocking fixes for 1.21+ clients (by RK_01)
• Tridents and banner pattern items show the correct 1.20 rarity in 1.20.5->1.21 (by EnZaXD)
• Fixed splash/lingering potions being invisible in 1.19 protocols (by EnZaXD)
• Fixed attribute keeping on respawn for <1.14 clients in 1.16->1.15 (by RK_01)
• Fixed show_item in translation components in 1.11->1.12 (by EnZaXD)
• Slightly improve on 1.10->1.11 fishing hook position desync
• The 1.9 cooldown indicator is now completely hidden in 1.8->1.9 (by lowercasebtw)
  • The minimize-cooldown has been removed
• Fixed wither and ender dragon bossbars not working in 1.8->1.9 (by EnZaXD)
• Added cancel-block-sounds config option to toggle the 1.8 block placement sound fix (by EnZaXD)

If you want to get larger version updates early, consider supporting me via https://viaversion.com/donate. See the previous update notes for more info.