Describe the bug
On our modded server, a player has started to crash immediately when logging on, when present in a chunk with copycats+ blocks, despite it seemingly working just fine up until that point for him and everyone else for days. The crash was specifically within those chunks, as when I teleported him away he was able to play without crashing again.
No one else playing on the server faced this issue as of yet, another player visited the same area and haven't crashed, but considering that that player haven't crashed prior to this either it might happen again to someone else.

Crash report: https://mclo.gs/LxLp2er

To Reproduce
Steps to reproduce the behavior:

1. Be present in chunks with some copycat blocks present.
2. Immediately crash upon login.

Expected behavior
No crash when within said chunks.

Desktop (please complete the following information):

• Minecraft Version: 1.20.1
• Mod Loader: Fabric
• Mod Version: 2.2.2+mc.1.20.1-fabric

Thank you in advance

Apologies, we might have found the culprit. Seems like this was caused by Sodium Shadowy Path Blocks mod, don't know if it's an incompatibility between them or if Copycats+ is mentioned in the log for some other reason, but removing SSPB the crash was no longer present.

I have this exact issue but on Forge 1.20.1, I opened an issue but they haven't helped, do you know if there is a mod similar to this one but for Forge? Or what could produce the issue? I am using emmbedium and additions.

I was able to deduce that mod being the issue after taking another look at the log, as it refers to the tesselating block being a dirt_path, and that mod affects paths. Do you have anything similar in your pack? Have you tried disabling any mods that affect lighting in any way and testing if it remains the same? Perhaps mods that affect embeddium in any way as well?
Looking at your issue, I have to point out that I'm also not using Create 6, as it isn't out on fabric just yet, so our issues might not be the same after all, as it seems you aren't able to result in an actual crash

I was able to deduce that mod being the issue after taking another look at the log, as it refers to the tesselating block being a dirt_path, and that mod affects paths. Do you have anything similar in your pack? Have you tried disabling any mods that affect lighting in any way and testing if it remains the same? Perhaps mods that affect embeddium in any way as well? Looking at your issue, I have to point out that I'm also not using Create 6, as it isn't out on fabric just yet, so our issues might not be the same after all, as it seems you aren't able to result in an actual crash

I see, first thanks for the reply. The main crash situation os the same but yeah we have create v6. I saw another user saying that on create v5 it solves, but I think its important or if copycats+ says its officially updated to v6 that it could work on v6.
I will try disabling some embbedium mods but no I don't have any mod that affects lightning as far as I remember. But thank you for the aswer and I will try disabling som eembeddium additions mods and such.