We setup a mc server with fabric and some mods. One of which is this.
It works with 4 out of 5 people, however with the last person we/he gets the following error shortly after connecting:
Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IllegalArgumentException: Unknown recipe serializer extraalchemy:potion_ring.

I don't know how relevant this is: In his first attempt to join he put the mods folder I provided for him as .zip inside the mods folder, but we changed this after his first attempt and the directory is definitely correct now.

What happened/how to reproduce

1. Install the newest build from CurseForge of extraalchemy
2. Start MC
3. Connect to a server that has extraalchemy installed.
4. -> crash

What should happen

1. Install the newest build from CurseForge of extraalchemy
2. Start MC
3. Connect to a server that has extraalchemy installed.
4. -> connect

Mod List:
https://pastebin.com/pZ1y5RaL

• Mod Version: extraalchemy-fabric-1.17-1.5.1
• MC Version: 1.17.1
• Fabric Version: Newest Version
• Fabric API version: Pastebin
• System: Windows 10
• Installation type: DedicatedServer

Additional context
See beginning.

Sounds like he has a mismatched version of the mod. Let's check the extra alchemy version he has installed: attach an in-game screenshot of the mod menu page or his latest.log file please

Thank you for your quick response.
We found the issue... Im a bit embarrassed that I have written this bug ticket...

Solution:
He didn't start MC with fabric and therefore no mods were loaded. I figured that after he said he had no Map (which he should have had)

Thank you!

Np