Minecraft Version

1.21.1

Mod Version

21.1.48

Mod Loader

Fabric

What environment are you running the mod in?

Client

Issue Description

• Attempt to join a singleplayer world
• Receive an "Invalid Player Data" message instead of connecting

Seems to happen only some of the time when joining a singleplayer world. Here's the relevant log line: https://mclo.gs/t8RV3rJ#L5068

Thanks for reporting this, definitely an issue on my end. A new version with the fix will be out soon.