I want to create a RLCraft dedicated server to play with my friends but it keeps crashing. It says:

Description: Exception in server tick loop
net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Defiled Lands (defiledlands)
Caused by: java.lang.ExceptionInInitializerError

I can launch the game without issues. Launching server is the problem.

Minecraft version :
1.12.2
Defiled Lands version :
1.4.3
Crash log : (link to pastebin or something similar, delete that line if it's not a crash)

https://pastebin.com/STJiN90t

Since that's a modpack, have you reported this to the modpack issue tracker?

Oh i didnt think of that sorry let me report to them.