MonstrumLocationManagerFix

Monstrum mods are fine by itself but it can have problems with other mods that adds locations.
There is sometimes duplication with location proxies so you may devote double offerings to summon a boss.
And there was problem with valheimcuisine's location too. And this mod fixes that.

MonstrumLocationManagerFix is a small BepInEx plugin for Valheim that fixes Therzie's Monstrum and MonstrumDeepNorth location registration at runtime.

What it fixes

In Therzie's location registration flow, LocationManager.Location.AddLocationToZoneSystem can use:

UnityEngine.Object.Destroy(...)

when removing the existing enabled LocationProxy from ZoneSystem.m_locationProxyPrefab.

In this path, deferred destruction can leave the old proxy alive until later in the frame while a replacement proxy is added immediately. That can cause duplicate or conflicting location proxy behavior.

This plugin changes that call to:

UnityEngine.Object.DestroyImmediate(...)

so the cleanup happens immediately during location setup.

Target mods

This plugin only patches loaded assemblies that belong to these plugin GUIDs:

Therzie.Monstrum
Therzie.MonstrumDeepNorth

It only targets this method:

LocationManager.Location.AddLocationToZoneSystem

How it works

This is a normal BepInEx plugin, not a preloader patcher.

At startup it:

Detects whether Monstrum and/or MonstrumDeepNorth are loaded.
Finds LocationManager.Location.AddLocationToZoneSystem in those assemblies.
Applies a Harmony transpiler.
Replaces Destroy(Object) with DestroyImmediate(Object) in memory.

Important behavior

Install location: BepInEx/plugins
Does not modify Monstrum.dll
Does not modify MonstrumDeepNorth.dll
Does not write marker files
Does not clear the BepInEx cache
Does not require anti-cheat whitelisting for modified Monstrum DLLs

Example log lines

Successful runtime patch:

Loading [MonstrumLocationManagerFix 1.0.0]
Patched Monstrum.LocationManager.Location.AddLocationToZoneSystem and replaced 1 Destroy call(s).
Patched MonstrumDeepNorth.LocationManager.Location.AddLocationToZoneSystem and replaced 1 Destroy call(s).

Already fixed in the loaded target assembly:

Verified Monstrum.LocationManager.Location.AddLocationToZoneSystem is already using DestroyImmediate.

Patch summary:

Applied runtime patch to 2 LocationManager method(s).

Scope and safety

This plugin is intentionally narrow.

No config file
No gameplay changes outside the targeted location proxy cleanup
No patching of unrelated mods
No permanent modification of other mods' files

Why this exists

An earlier version solved the issue by rewriting other mods' DLL files on disk. This version keeps the same fix but applies it at runtime instead.