While fiddeling with custom mob's table and encountering zombies with weird pumpkin head fetish (the default table works for some reason).
Now the mod just crashes the game when trying to load into the world or create new one from the menu.
For the game to not crash and have it work normally, I have to disable your mod.
Reinstalling and "Yeeting" out an entire mod configs folder did not work.
Quick note: I am using 1.2.1 version of the mod, for 1.19.2 version of minecraft.
Here is the crash log:

Time: 2023-11-16 21:45:50
Description: Exception in server tick loop

java.lang.ArithmeticException: / by zero
at net.smileycorp.hordes.common.hordeevent.capability.HordeSavedData.getCleanData(HordeSavedData.java:105) ~[The-Hordes-1.19.2-1.2.1.jar%23416!/:1.19.2-1.2.1] {re:classloading}
at net.smileycorp.hordes.common.hordeevent.capability.HordeSavedData.lambda$getData$1(HordeSavedData.java:87) ~[The-Hordes-1.19.2-1.2.1.jar%23416!/:1.19.2-1.2.1] {re:classloading}
at net.minecraft.world.level.storage.DimensionDataStorage.m_164861_(DimensionDataStorage.java:43) ~[client-1.19.2-20220805.130853-srg.jar%23445!/:?] {re:classloading}
at net.smileycorp.hordes.common.hordeevent.capability.HordeSavedData.getData(HordeSavedData.java:87) ~[The-Hordes-1.19.2-1.2.1.jar%23416!/:1.19.2-1.2.1] {re:classloading}
at net.smileycorp.hordes.common.hordeevent.HordeEventHandler.serverTick(HordeEventHandler.java:80) ~[The-Hordes-1.19.2-1.2.1.jar%23416!/:1.19.2-1.2.1] {re:classloading}
at net.smileycorp.hordes.common.hordeevent.HordeEventHandler_serverTick_ServerTickEvent.invoke(.dynamic) ~[The-Hordes-1.19.2-1.2.1.jar%23416!/:1.19.2-1.2.1] {re:classloading,pl:eventbus:B}
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:73) ~[eventbus-6.0.3.jar%2385!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:315) ~[eventbus-6.0.3.jar%2385!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:296) ~[eventbus-6.0.3.jar%2385!/:?] {}
at net.minecraftforge.event.ForgeEventFactory.onPreServerTick(ForgeEventFactory.java:844) ~[forge-1.19.2-43.3.5-universal.jar%23450!/:?] {re:mixin,re:classloading}
at net.minecraft.server.MinecraftServer.m_5705(MinecraftServer.java:804) ~[client-1.19.2-20220805.130853-srg.jar%23445!/:?] {re:mixin,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,re:classloading,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,pl:mixin:A}
at net.minecraft.client.server.IntegratedServer.m_5705(IntegratedServer.java:84) ~[client-1.19.2-20220805.130853-srg.jar%23445!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:blueprint.mixins.json:client.IntegratedServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:654) ~[client-1.19.2-20220805.130853-srg.jar%23445!/:?] {re:mixin,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,re:classloading,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,pl:mixin:A}
at net.minecraft.server.MinecraftServer.m_206580_(MinecraftServer.java:244) ~[client-1.19.2-20220805.130853-srg.jar%23445!/:?] {re:mixin,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,re:classloading,pl:accesstransformer:B,xf:fml:xaeroworldmap:xaero_wm_minecraftserver,xf:fml:xaerominimap:xaero_minecraftserver,pl:mixin:A}
at java.lang.Thread.run(Thread.java:833) [?:?] {re:mixin}

great mod, keep up the good work!

I had a similar issue with trying to make a custom raid night based around John Mod Reborn, but I was able to resolve it just by uninstalling the mod and fixing the config. I never had the issue in which I cannot make new worlds.

Did you set hordeSpawnDays in the config to 0?

The minimum is 1, but I'll add in error checking for that.

As for the zombies having pumpkin heads, that means there's an error in your script or table, check the hordes.log file.

Should be fixed as of 1.2.1a.