Context and Solution:
As the "counter attack" skill is enabled, it causes a crash whenever a player gets hit by a mob, projectile or explosion. When you get crashed (if you are the player who got hit) you wil not be able to re-enter the server because the entity who hit you will tick. To solve this, you may enter from another account, or it can be a friend, that account must go to the zone where you disconnected (crashed), that will load the entity and stop the ticking so you can enter again. To prevent this, just disable the "counter attack" skill.

Request:
Now, I wanted to ask a dev to, first, update the mod and solve this problem. Second, if there's a way to disable the skill for everyone in the server in order to avoid any problem.

Thanks!

This mod is not being updated anymore i suggest you use the fork here , if you are wondering why Dplayend lost mod source but the issue is fixed here along with more features added
https://github.com/Senior-S/JustLeveling-Fork
he should really archive this