Server side broke in Nether/incompatibility with mods that use entity to create structures

[BlackAures1]

Problem: I'm developing a modpack 1.19.2 Forge and some point Nether decided to randomly broke the game on some chunks. Most likely on those where some mod tries to create a structure using an entity. Incontrol tries to control the spawn of this entity and fails.

What is the breakdown: after join to Nether client side can destroy blocks, move, open inventory and so on, but the server side does not work - chunks do not load further, all the entities frozen, the player does not receive damage, when saving the world is an infinite load or the game does not respond. In logs only "Timed out waiting for world statistics" and no crashreport file. Video.

My guess - some entity or any other object in a random chunk near the player is broken and causes dead loop, but I have no idea what mod is it. I had a very similar bug a long time ago (https://github.com/Shadows-of-Fire/Wither-Skeleton-Tweaks/issues/35 ), but I don't have these mods now.

Incontrol settings: spawn.json spawner.json special.json loot.json

Here are two files (1, 2) from visualvm.

A response from one of the Curseforge moderators who helped me find the problem:

[McJty]

Not 100% sure why yet but it is caused by your two rules in special.json. It will be fixed by removing those or else by adding "result": "replace" to both rules

[BlackAures1]

Addendum of "result": "replace" didn't help. I just deleted special.json and use another mod to reinforce the mobs from Nether/End