[Issue] worldserver.exe crashing when using mod-multibot-bridge

[hze3]

Issue type *

Bug

Server/AzerothCore version

No response

Description *

Got disconnected from server whilst running Maraudon in a Random Dungeon Finder, however I have seen the server crash previously even when not logged in and doing anything myself.

I've confirmed that without the mod-multibot-bridge module, the server does not experience any crashing. 

Currently running other modules:
mod-playerbots
mod-ah-bot-plus
individualprogression

Steps to reproduce

1: Launch server.
2: Wait a while. Server was up for about 1 hour and 30 minutes for me.
3: Get disconnected randomly.
4: Check worldserver.exe and see its not running in task manager.

Expected behavior *

Hopefully not crash!

Actual behavior / Errors

3258e4c78284_worldserver.exe_[3-5_11-47-15].txt
3258e4c78284_worldserver.exe_[3-5_11-47-15].dmp

Crashlog / Gist link (optional)

No response

Screenshots

No response

Pre-submission checklist *

• I searched for existing issues that match mine.
• I tested with the minimum set of addons/changes.
• I provided reproduction steps and/or relevant logs.

Additional context

Server running on Windows 11. Not really sure what else would be relevant here, but happy to help answer any questions.

[Wishmaster117]

Hi,
I gave a look at your carsh logs, here is the result:

Immediate Cause

The worldserver.exe crashes with an ACCESS_VIOLATION C0000005 (invalid memory read/write) in Creature::CanCreatureAttack (Creature.cpp:2725), triggered from the following call stack:

SmartAI::UpdateAI → Creature::SelectVictim → ThreatManager::GetCurrentVictim
→ ThreatReference::ShouldBeOffline → Creature::CanCreatureAttack → CRASH

The faulting thread is a MapUpdater worker thread, during Map::UpdateNonPlayerObjects.

---

Probable Root Cause

A SmartAI creature holds in its threat list an invalid reference (despawned, disconnected, teleported, off-map, or already freed memory target). When the server attempts to verify whether the creature can still attack that target via CanCreatureAttack(), it dereferences a null or dangling pointer — confirmed by RCX = 0x0 in the registers at the time of the crash.

The build being a Playerbot branch, a bot or a bot-related target is the likely trigger for this corrupted state.

---

Role of the mod-multibot-bridge Module

The bridge is passive by design: it sends no playerbot commands autonomously. It acts solely as a receiver/interpreter for incoming MBOT addon messages via OnPlayerCanUseChat.

Traffic type | Automatic? | Combat crash risk -- | -- | -- HELLO / PING / GET~ROSTER / GET~STATES | Yes (login/UI refresh) | Very low RUN~COMBAT / RUN~RTI / RUN~POSITION | No (user action) | Possible trigger

The bridge does not appear in the crash stack, ruling out direct responsibility. It could be an indirect trigger only if a RUN~ command forced a bot into combat just before the crash.

---

Priority Fix Targets

Add guards in ThreatReference::ShouldBeOffline() or before the call to CanCreatureAttack():

cpp

// Check before any call to CanCreatureAttack:
if (!target || !target->IsInWorld() || target->GetMapId() != creature->GetMapId())
    return true; // consider offline

Relevant files:

• src/server/game/Combat/ThreatManager.cpp (lines 116, 246)
• src/server/game/Entities/Creature/Creature.cpp (line 2725)
• src/server/game/Entities/Unit/Unit.cpp (line 11492)

---

Recommended Diagnostic Plan

1. Bridge disabled, same bots in combat → crash persists = bridge ruled out
2. Bridge active, without MultiBot addon → crash persists = pure core/playerbots bug
3. Bridge + addon, without any RUN~ commands → crash persists = bridge-independent bug
4. Temporary logs on RUN~ commands with timestamps to correlate with crash time

---

Conclusion

The crash is most likely a threat list management bug in the playerbots module, exposed when a target abruptly leaves combat or the map. The mod-multibot-bridge module is unlikely to be the direct cause, unless it issued a RUN~COMBAT or RUN~RTI command just before the crash.

[hze3]

Ran my server all day yesterday without the bridge installed, but using the deprecated multibot addon. No crashes all day.

Testing bridge active, without multibot addon shortly. Will update if there's another crash with logs attached.

Updated to the latest build this morning as well.

[Wishmaster117]

Ran my server all day yesterday without the bridge installed, but using the deprecated multibot addon. No crashes all day.

Testing bridge active, without multibot addon shortly. Will update if there's another crash with logs attached.

Updated to the latest build this morning as well.

Ok we keep this issue opened so.

[hze3]

Server crashed overnight. It ran for around 19 hours.

No-one was logged in at the time, and during the day no-one had the addon enabled. Commands were sent to rndbots throughout the day, but minimally. Pretty much only used 'summon', and that's it.

3258e4c78284_worldserver.exe_[5-5_5-34-10].dmp
3258e4c78284_worldserver.exe_[5-5_5-34-10].txt

[Wishmaster117]

Server crashed overnight. It ran for around 19 hours.

No-one was logged in at the time, and during the day no-one had the addon enabled. Commands were sent to rndbots throughout the day, but minimally. Pretty much only used 'summon', and that's it.

3258e4c78284_worldserver.exe_[5-5_5-34-10].dmp 3258e4c78284_worldserver.exe_[5-5_5-34-10].txt

Hi,
Based on the crash dump, I do not think this crash is directly caused by mod-multibot-bridge.

The crash happened after ~19 hours of uptime, overnight, with no real player logged in at the time. During the day, the addon was not enabled by anyone, and only minimal commands were sent to random bots, mostly summon.

The crash stack points to AzerothCore combat/threat handling:

Creature::CanCreatureAttack
ThreatReference::ShouldBeOffline
ThreatManager::GetCurrentVictim
Creature::SelectVictim
CreatureAI::UpdateVictim
SmartAI::UpdateAI
Creature::Update
Map::UpdateNonPlayerObjects
Map::Update
MapUpdater::WorkerThread

The exception is an access violation inside:

Creature::CanCreatureAttack

There is no mod-multibot-bridge function in the active crashing stack.

The bridge does not directly manipulate ThreatManager, ThreatReference, Creature::SelectVictim, or Creature::CanCreatureAttack. For combat/RTI/loot endpoints, it only forwards validated commands to the existing playerbots command handler, essentially the same kind of command path as a whisper command.

So my current interpretation is:

• Direct crash location: AzerothCore / playerbots threat or creature victim selection.
• Direct bridge involvement: unlikely.
• Possible indirect trigger: only if a bridge command caused a bot to enter combat, pull, move, teleport, or otherwise leave stale threat references behind.
• In this specific case, since no addon was enabled and only minimal summon commands were used, the bridge seems unlikely to be the root cause.

The more likely issue is a stale or invalid threat reference involving a bot/random bot or another unit, which later caused a creature SmartAI update to call Creature::CanCreatureAttack() with an invalid/null object during victim selection.

I would investigate playerbot/random-bot lifecycle cleanup around:

• bot summon / teleport,
• bot despawn or map change,
• logout/unload of random bots,
• threat list cleanup when bots are removed from world,
• creatures retaining threat references to bots that are no longer valid.

In short: the bridge may be able to trigger this kind of bug if it sends combat-related commands, but this crash dump does not show the bridge as the direct cause, and the reported circumstances make the bridge/addon path unlikely.

Maybe you can report those crash in Playerbots git.

[hze3]

Just adding a further update that since removing the bridge module, worldserver crashes are no longer occurring. Servers been stable for over 2 days now.

I expect if I added it again, and used the addon alongside the bridge module, I bet I can get it to crash pretty reliably within an hour or so.

This really is the only thing I'm changing each time I add or remove the module. So if it's not the bridge module thats directly triggering it, its certainly upsetting something within playerbots.

[Wishmaster117]

I'll try to make a closer look, but it's difficult to know what's happening since crash logs don't show any bridge default and Bridge don't send stuffs automatically, only when you use the ad don

[hze3]

Cheers, I appreciate its difficult to determine what is triggering it. For now we're just back to playing with the standalone multibot addon and no bridge, crash-free ever since. I'm happy to bring it up with the rest of the playerbots group and run some tests at some point though if you need any help reproducing it.

We'd love to use the bridge and the chatless addon, it looks so much better to use overall to be honest.

[Wishmaster117]

Cheers, I appreciate its difficult to determine what is triggering it. For now we're just back to playing with the standalone multibot addon and no bridge, crash-free ever since. I'm happy to bring it up with the rest of the playerbots group and run some tests at some point though if you need any help reproducing it.

We'd love to use the bridge and the chatless addon, it looks so much better to use overall to be honest.

Any help is welcome. I do not think the bridge itself is causing the crashes, but it may be exposing a weakness in the Playerbots code. For example, sending an action to an invalid bot could trigger errors.

If I were able to get traces with more details, it would be much easier to fix the issue by adding safeguards or similar checks.