BGSWaterCollision - CrashFix

Description

BGS Water Collision Crash Fix stops a crash caused by Skyrim's water system (waterfalls and placeable water). When a cell unloads, the game can free a waterfall's collision data while a background thread is still walking the global water list and asking each object "are your collision planes ready?". That thread then reads an already-freed object and the game crashes. It is a timing-dependent use-after-free race, so it strikes at random and is hard to reproduce.

This mod works at the DLL level. It does not edit meshes, cells, or any game files, so it stays compatible with everything and can be placed anywhere in your load order. It is a runtime safety net, not an esp.

This is a known water, waterfall, and Havok crash pattern, not a one-off error. It shows up most in water-heavy areas such as Solstheim and the Forgotten Vale, and tends to be more likely with mods that add or change a lot of water and FX meshes water and waterfall replacers, particle and mesh patcher output (ParallaxGen, PG Patcher, CS Particle Patch), Water for ENB, Natural Waterfalls, and sometimes DynDOLOD or Occlusion. None of these is "the cause" they only widen the timing window of a race that already exists in the base game, so no single mod points to it exactly. A full crash log is the only way to be sure what is involved.

Supports Skyrim SE 1. 5. 97 and AE 1. 6. 1170 in one DLL.

(VR: the code path is in place but has not been tested in-game yet.)

Does this fix my crash?

The reliable sign is the object and the thread, not the exact instruction:

EXCEPTION_ACCESS_VIOLATION  on a BSJobs::JobThread

object: BGSWaterCollisionManager::bhkWaterfall

or: BGSWaterCollisionManager::bhkPlaceableWater

The faulting line is usually "cmp qword ptr , 0", but the same bug can also appear as a call to a null or garbage address in the same water code. If you see either water object above on a BSJobs::JobThread, this is the crash this mod prevents - both water types are covered.

Installation instructions

Install with your mod manager and enable the mod. No configuration needed.

How it works

Right before the engine checks a water object, the mod safely tests whether that object is still valid. If it is, the check runs exactly as the game intended waterfalls behave normally. If the object has already been freed, the mod tells the engine "not ready", which is the same answer the game itself gives for water that is not re