I went to add the new 1.20.1 version to our server, and all went smoothly until we tested placing a fairy light.
Here's the pastebin: https://pastebin.com/TnjvdQMT

Ty for your time and hard work, love your mod!

Use Embeddium, it's better, more stable and has better compatability. You won't have to worry anymore and will have better performance, in my opinion.