Describe the bug
When playing with servercore installed, all hostile mobs stop spawning.

Reproduce
Steps to reproduce the behavior:

1. Install servercore

Expected behavior
Hostile mobs should spawn

Versions -Latest is not a version!
ServerCore: 1.5.1 forge
Minecraft: 1.20.1

Mod incompatibilities
There are no other mods installed.

Can you provide your config.yml / log file? I know of a bug with faulty configurations (errors would be logged) that could potentially cause this.

Other than that, I am unable to reproduce this.

This is my log here (changed to .txt for github) config.txt

There are a lot of modded mob categories in there that the mod would be unable to recognize if you are running with no other mods installed. Try removing these.

    - category: 'GLARES'
      mobcap: 15
      spawn-interval: 1

    - category: 'RASCALS'
      mobcap: 1
      spawn-interval: 1

    - category: 'WILDERWILDFIREFLIES'
      mobcap: 56
      spawn-interval: 1

    - category: 'WILDERWILDJELLYFISH'
      mobcap: 30
      spawn-interval: 1

    - category: 'WILDERWILDCRAB'
      mobcap: 25
      spawn-interval: 1

    - category: 'WILDERWILDTUMBLEWEED'
      mobcap: 10
      spawn-interval: 1

    - category: 'ha_fish'
      mobcap: 5
      spawn-interval: 1

    - category: 'ha_fish_underground'
      mobcap: 5
      spawn-interval: 1

    - category: 'ha_squid'
      mobcap: 5
      spawn-interval: 1

    - category: 'ha_squid_underground'
      mobcap: 5
      spawn-interval: 1

    - category: 'ha_jelly'
      mobcap: 5
      spawn-interval: 1

    - category: 'ha_jelly_underground'
      mobcap: 3
      spawn-interval: 1

    - category: 'ha_shark'
      mobcap: 5
      spawn-interval: 400

    - category: 'crustacean'
      mobcap: 5
      spawn-interval: 1

    - category: 'crustacean_underground'
      mobcap: 3
      spawn-interval: 1

    - category: 'ha_critter'
      mobcap: 5
      spawn-interval: 1

same problem, had to remove servercore from the server and i started looking hostile mobs again

If you have this problem please upload your latest.log of an instance of the game where mobspawning stopped working.
I wasn't able to reproduce this.

servercore 1.5.1+1.20.1
2024-05-29-6.log.gz

of course i have a lot of mods but hope this helps you

That log file is cut off way before the vast majority of actual modloading happens, so it doesn't help that much.

I noticed that in 1.5.1 there's a bug if you boot up the game with an incorrect config (which it will show errors for in the logs) or removed any dynamic settings in the config, it wouldn't properly initialize the values, meaning dynamic settings can be set to -1.

Use /sc status to check this. If any values are set to -1, there's something wrong. For example mobcap percentage at -1 would be your reason as to why mobs aren't spawning. This should be fixed with daed791, but I haven't extensively tested that just yet.

I can't guarantee that this is the same issue, it just seems the most likely.

The issue has been resolved for me by removing the unnecessary categories it seems.

Delete and regenerate the configuration file
will runs successfully and no “-1” occurs