Describe the bug
When starting the Server (it's the standard Minecraft server with Forge), everything seems to startup fine. The Moment a Player joins, the Server crashes, with the error report linked. I only updated this Mod, before that it worked.
The player is immediately disconnected.

To Reproduce

• Run the Server
• Join with any Player

Expected behavior
Not Crash upon joining the Server

Logs
Crash report here.

Additional context
Happens on any 3.0.x of the Mod.
Minecraft Version is 1.12.2, Forge 14.23.5.2860