Mod loader

Fabric

Minecraft version

1.21.4

Mod version

4.0.0-alpha.3

Affected mods

• Elytra Trims
• Extensions

Bug description

When using the latest version available on Modrinth on a Fabric server, vanilla clients don't properly render the elytra.
From the mod's description, it should be optional for vanilla clients on servers with the mod. These two screenshots were taken on the same running server. This server had Elytra Trims installed before updating to 1.21.4. That said, in the screenshots I took, I had trimmed the elytra after the update.
My modded client:

Vanilla 1.21.4 client:

I was also able to reproduce the bug by creating a singleplayer world, applying a trim, then loading that same singleplayer world in the same client with the mod disabled.

Steps to reproduce

1. Install Elytra Trims on Fabric 0.16.10 server
2. Join server with vanilla client
3. Observe trimmed elytra

I think this line from the server's log might be a hint?
[18:29:43] [Server thread/ERROR]: Tried to load invalid item: 'No key description in MapLike[{range:256.0f,sound_event:{sound_id:"minecraft:intentionally_empty"},use_duration:140}] missed input: {"minecraft:instrument":{range:256.0f,sound_event:{sound_id:"minecraft:intentionally_empty"},use_duration:140}} missed input: {"minecraft:container":[{item:{count:5,id:"minecraft:flow_armor_trim_smithing_template"},slot:0},{item:{count:4,id:"minecraft:bolt_armor_trim_smithing_template"},slot:1},{item:{count:2,id:"minecraft:netherite_upgrade_smithing_template"},slot:2},{item:{count:1,id:"minecraft:eye_armor_trim_smithing_template"},slot:3},{item:{count:2,id:"minecraft:dune_armor_trim_smithing_template"},slot:4},{item:{count:2,id:"minecraft:wild_armor_trim_smithing_template"},slot:5},{item:{count:1,id:"minecraft:ward_armor_trim_smithing_template"},slot:6},{item:{count:1,id:"minecraft:silence_armor_trim_smithing_template"},slot:7},{item:{count:1,id:"minecraft:tide_armor_trim_smithing_template"},slot:8},{item:{count:2,id:"minecraft:coast_armor_trim_smithing_template"},slot:9},{item:{count:1,id:"minecraft:spire_armor_trim_smithing_template"},slot:10},{item:{count:3,id:"minecraft:shaper_armor_trim_smithing_template"},slot:11},{item:{count:4,id:"minecraft:wayfinder_armor_trim_smithing_template"},slot:12},{item:{count:4,id:"minecraft:host_armor_trim_smithing_template"},slot:13},{item:{count:1,id:"minecraft:raiser_armor_trim_smithing_template"},slot:14},{item:{count:2,id:"minecraft:raiser_armor_trim_smithing_template"},slot:15},{item:{components:{"!minecraft:lore":{},"minecraft:custom_data":{CustomSound:[I;703436305,1713062985,-1144469405,1234964165]},"minecraft:custom_name":'"Yipee"',"minecraft:hide_additional_tooltip":{},"minecraft:instrument":{range:256.0f,sound_event:{sound_id:"minecraft:intentionally_empty"},use_duration:140}},count:1,id:"minecraft:goat_horn"},slot:17},{item:{count:1,id:"minecraft:totem_of_undying"},slot:18},{item:{count:8,id:"minecraft:enchanted_golden_apple"},slot:22},{item:{count:4,id:"minecraft:ancient_debris"},slot:23},{item:{count:64,id:"minecraft:diamond_block"},slot:25},{item:{count:53,id:"minecraft:diamond_block"},slot:26}]}'

Modded server logs are here: latest.log.
Log from vanilla client on modded server: https://mclo.gs/q1ClkBa
Log from vanilla client on modded singleplayer: https://mclo.gs/o9GWaX0

Relevant logs

No response

I'm glad this is already known, and that a resource pack is coming :) I'll encourage my servermates to use the mod (most of them already do).
Even being able to see basic trims on vanilla is a huge feature vs. earlier 1.21 versions, so I'm excited to see what you're cooking!

TL;DR: This is how it is on vanilla now. Take it a subtle hint for vanilla clients to stop being cringe and install Fabric, but there will be a resourcepack with limited features.

This is known and specific to 1.21.4, since trims can now be added to any armor in vanilla. There will be a resourcepack published along the mod that allows seeing dyed color and trims (but not cosmic, glow effects and banner patterns) on vanilla.