[Bug]: got a server chunk crash on Alex Caves via MC 1.21.1 and neoforge 21.1.224

[musicbynumbers]

What had happened?

Hi! Was just trying out the 1.21.1 version of Alex cave's and ran into the below crash upon flying around for a bit on a new world to test it. It might be something else but started happening when adding alex caves and went away without it..

https://mclo.gs/3zyJMPH

Let me know if you need anything else. thanks!

Minecraft Version

1.20.1

Alex's Cave Version

2.0.2

Citadel Version

2.7.0

Game Log / Crash Report

https://mclo.gs/3zyJMPH

Check List

• I have removed Optifine.
• I have installed other mods (Please also provide mod list)
• This is a conflict with other mods and no issue occurred when running standalone.