Logs:
crash-2023-07-21_02.24.35-server.txt

debug.log

latest.log

MC Launcher error code:
The game crashed whilst exception ticking world
Error: java.lang.NullPointerException: Cannot invoke "com.github.kay9.dragonmounts.dragon.breed.DragonBreed.sizeModifier()" because the return value of "com.github.kay9.dragonmounts.dragon.TameableDragon.getBreed()" is null (exit-Code:-1

1. just hatch a dragon egg..

found it out only works on forge 1.20.1 - 47.1.3

Duplicate of #175