The number of endermans that spawn on the other side is killing my NAS cpu :).
How can I adjust the freqvence of each "mod replace" ?

I assume is here, but I dont see a reasoon for so many enderman replacements ... https://github.com/elBukkit/MagicPlugin/blob/master/Magic/src/main/resources/examples/otherside/worlds/otherside_mobs.yml

Also .. is Magic overridding my paper config mob limits ?

In the “fallback” rule you can see the vast majority (about 10x the next mob) of mobs are replaced with enderman. It’s supposed to be the home dimension of enderman, so there should be a ton of them there, similar to the end.

I do not know how the paper mob limits work, but I would not be surprised if replacing mobs breaks them since Paper doesn’t really know what kind of mob is ultimately going to be spawned.

So you could try reducing the probability there, but I suspect there is some larger problem and you’ll just get a lot of other mobs but still have more than you want.

Does this only happen in your spawn chunks, or does it look like this everywhere in that world?

I did not test more than what I did last time (spawn) .. as my server was very laggy.
I will try again ...so:
I will need to change this:
enderman: 1000
to something like this ?:
enderman: 10

Also ... below ... I see the probability (assume 0.9 = 90%) ...
warlock: 10 means ? 10% out of that 90% ?

rabbit:
      class: Replace
      target_type: rabbit
      probability: 0.9
      replace_type:
        warlock: 10
        dark_wizard: 1
        killer_bunny: 20

PS: I belive only bukit.yml has the mob limits .... I have as setup 50 monsters so I guess I had 50 enderemans ? :D

Yes you can try that- I suspect what will happen is you'll just get a larger variety of too many mobs, but maybe there is something special about enderman that they're not despawning for some reason?

The probability property is a percentage, so that's right 0.9 = 90%. So this replace rule has a 90% chance of running, when it runs it picks a replacement type from its probability table.

The probability tables work with weights, not really direct percentages. So the 10 there doesn't mean 10%, it means 10 / 31 (where 31 is the total of all the weights in the table). So they are all relative to each other, basically.

It did not solve it - in 2 mins I got zzzbilion Endermans!
https://ibb.co/jhQ5CGP

That's really nuts.. hmmm I wonder if it's because of the grass? I've never tested this config with grass but there could be some vanilla complication. Do you have the chunk populator enabled too (it probably missed the spawn chunks if so)

And it's still just enderman? I guess maybe try taking all the enderman out of the config completely?

Perfect! Thank you!
The probability tables work with weights, not really direct percentages. So the 10 there doesn't mean 10%, it means 10 / 31 (where 31 is the total of all the weights in the table). So they are all relative to each other, basically.
Thats was my fallback option :)

Grass ?
I do have the chunk master. I used it to preload the chunks, but it was not working at that time ... on any world.
There were a few other mobs as well (mostly spiders, ghasts)... but .. as you can see ... you barely see between endermans :D

PS: If I read well here they were around 300 endermans and 1000 mobs more than before I tp to the other side ... https://timings.aikar.co/?id=7a6cde42eb454348a0f2259196a4ecc0#timings

Sorry I kinda dropped the ball on this one! Please re-open if you're still having issues or want help.

Mob spawning is really tricky business as it turns out, so I may not really have a full-proof solution to them running out of control :(