Unexplained crashes with no change in missions or settings

[Barnacles]

Combat box has been hosting MP missions for several years. Recently, (about 1 month ago) we've been having unexplained crashes, where a mission will just kick all the players and end.

This first happened on some missions which were generated by our campaign software but since the first load of crashes, our missions which have not changed for years, have started crashing too.

We have tried everything and still they crash.

I've attached a copy of the mission that just failed.

These problems do not seem to be associated with a particular version of the game, they occurred before and after the previous update (6.001) but didn't start until many weeks after the release of the previous version.



Our specifications.

AMD Ryzen 9 7950X3D 16-Core Processor             4.20 GHz
192 GB (191 GB usable)
64-bit operating system, x64-based processor
Windows Server 2022 Standard
OS Build 20348.3932

big-normandy-campaign-day-030.zip

This is additional and separate to the issue at this link 

 

Edited July 22 by Barnacles

[Barnacles]

dogfight.2025-07-21_21-25-21_01.zipTrack at the moment of the crash

 

Additionally, here are some crash dumps from several of our crashes.

CrashDumps.zip

[kiwi_d]

Dear CB admins...I have been trying to re-enter your server after its latest crash..I am having no luck in finding the allied spawn points that were present prior to said crash..

I have enclosed a screenshot and highlighted where they were...

Can you please explain how i should join the allied coalition..

Regards..

[=DW=_BIRDD0G]

I really want to help the CombatBox team find the root cause of these issues.  I do some root cause analysis in my day job.  I'll fire some shots in the dark, maybe something will stick.

Crash Summary
Type: Access violation (0xc0000005)
Error: INVALID_POINTER_READ
Offending address: DServer.exe+0x325bc0
Instruction: movss xmm0,dword ptr [rcx+3F4h]
Crash cause: Attempted to read from an invalid pointer (RCX = 0x0), i.e., a null pointer dereference.

What This Means
The dedicated server (DServer.exe) tried to read a floating-point value (movss) from memory offset 0x3F4 of a null object (rcx == 0x0), which is not allowed → instant crash.

This typically means:

A missing or deleted object was still being accessed.

Some subsystem (like networking, mission logic, or AI) expected a valid pointer but got null.

These suggest the crash may relate to a client connection event — likely a disconnection, maybe even during object cleanup or reassignment.

Likely Causes
1. Client Disconnect / Netcode Bug
Something in the net.dll (network layer) or IL-2’s own DServer code failed to check a pointer before using it, possibly triggered by:

Sudden player disconnect

Malformed or delayed packet

AI/client entity timing out during mission

2. Custom Scripts or Mods
If you're running a custom scripted mission or any mods that touch multiplayer entities or networking, they might be involved. Invalid or unregistered references can easily cause this.

3. Memory Corruption or Race Condition
If you’re running multiple threads (e.g., many clients or AI) or mods that manipulate memory unsafely, that could be a root cause.
 
In my environment, errors like

 ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s

usually mean you have a memory overload or bad RAM stick.  I think I saw you have 192GB RAM, perhaps you have enough to try removing a few to rule out a hardware fault.  RAM errors can be pretty unpredictable, which fits the behavior.  This wouldn't be my first thought for this situation though.

 

OS Considerations

I also noted you are using Windows Server, which is a very complex OS with a broad application set.  It's great, but by default it is really locked down.  Perhaps there is some OS network or firewall setting that is too secure to allow Dserver to breathe.  Have you ever tried running this on vanilla Win10 or 11?  I doubt 1CS is developing DServer with Windows Server in mind.

 

Track File Analysis

I noted of the two server days that I have in which a server crash occurred, both showed the final message in the .eng file being:

1081:Capture!
1082:Airborne troops have been deployed to capture <objective name>

the objective name was different, but in both cases the message was related to airborne troops.  Sketch asked to add the feedback in the IL2 thread.  If you have more track files I can look at those too.  Add any dserver logs pr tracks to the thread and I'll keep shooting in the dark 

Edited July 22 by =DW=_BIRDD0G

[2/JG26_natris]

The biggest issue is that this problem is known by the developers for months, but there is zero communication from them. They can request any information they want, they can add additional logs/provide custom build with enabled memory checks etc due to how monstrous the server is, yet they chose to just sink significant portion of their online player base. I guess the online scene is too small and it is not worth for them to build goodwill  
 

[LukeFF]

2 hours ago, 2/JG26_natris said:

The biggest issue is that this problem is known by the developers for months, but there is zero communication from them. They can request any information they want, they can add additional logs/provide custom build with enabled memory checks etc due to how monstrous the server is, yet they chose to just sink significant portion of their online player base. I guess the online scene is too small and it is not worth for them to build goodwill  

 

That is not the case at all. CB had some issues a few weeks ago, we looked into it, and AFAIK, that issue is now resolved. We do our best to provide support to server admins when these issues arise, but ultimately, it is up to each server admin to ensure their missions are capable of running without crashing, especially since we have not updated anything for months now and other servers do not have these issues.

[354thFG_Leifr]

Hi.

Please find within the download link a track file. It contains a recording of the second crash on CB; nothing untoward had happened, no combar or otherwise, the server had just started up.

 

https://we.tl/t-f8t6cBh2gD

 

Hope it helps.

[Fideler_Fuchs]

Hello there,

track File from the first crash on CB today.

Just made a pass on a Spitfire...

 

Last Log entry:

754:Capture!
755:Airborne troops have been deployed to capture Falaise Encampment

 

Regards

Tracks.zip

Edited July 22 by 2./JG3_Fideler_Fuchs

[Barnacles]

25 minutes ago, LukeFF said:

 

That is not the case at all. CB had some issues a few weeks ago, we looked into it, and AFAIK, that issue is now resolved. We do our best to provide support to server admins when these issues arise, but ultimately, it is up to each server admin to ensure their missions are capable of running without crashing, especially since we have not updated anything for months now and other servers do not have these issues.

Yes @2/JG26_natris Luke is right, the Developers have not "ignored" us. They helped us initially with a problem with one map. However our issues have persisted globally on our server.

We in no way think we're owed special treatment, but we've looked for nearly 2 months now and found no explanation ourselves. If 1C are able to help, (recognising that they're busy with the new game) it'd be greatly appreciated though, and if we are able to solve this issue it will enhance the experience of many people playing IL2 GB online. We (the CB staff) will of course continue to devote our resources to coming up with a solution, but we want our missions to work, and they did for many years. It may be something to do with our hardware, but similarly, it worked perfectly before. So me raising this bug report is in hope of the Devs being able to make sense of the crash dumps and ID something that wouldn't be obvious to us.



 

[Alonzo]

50 minutes ago, LukeFF said:

 

That is not the case at all. CB had some issues a few weeks ago, we looked into it, and AFAIK, that issue is now resolved. We do our best to provide support to server admins when these issues arise, but ultimately, it is up to each server admin to ensure their missions are capable of running without crashing, especially since we have not updated anything for months now and other servers do not have these issues.

 

Hi Luke, what's the best way for us to get support with this issue? Is it this thread, or something else?

 

Our server and dynamic campaign were stable for a long time before we ran into the current issues, and we have now disabled most of the interesting stuff happening in our campaigns, trying to remove elements that would cause a problem. At the moment, though, dserver just outright crashes, while running a mission that has been put through the 1C 'resaver' utility and is a 'good' mission as far as we know. The crashes seem to be random -- sometimes the server will run great for multiple 3-hour missions, other times it will crash after just 45 minutes of a mission. We're not changing anything in between, and we've run a hardware test to rule out memory or CPU errors.

[=DW=_BIRDD0G]

still seeing the same trend, is it expected that this same message would be the last entry in the mission logs?

 

Day-09, duration 2:12

1081:Capture!
1082:Airborne troops have been deployed to capture Falaise Encampment

 

Day-30, duration 0:38

732:Capture!
733:Airborne troops have been deployed to capture Arromanches Mulberry B

Day-39, duration 1:49

754:Capture!
755:Airborne troops have been deployed to capture Falaise Encampment
 

Day-41, duration 0:10

782:Capture!
783:Airborne troops have been deployed to capture Falaise Encampment
 

[LukeFF]

5 hours ago, Alonzo said:

Hi Luke, what's the best way for us to get support with this issue? Is it this thread, or something else?

 

Regingrave would be the person here you want to message directly. 

[354thFG_Leifr]

@Regingrave-

[kiwi_d]

@Regingrave-

[Denum]

This started right around 5.507. Few days before the patch was out for download. 

 

Not sure if there's any back end changes that would coincide with that but 2 weeks prior the CB server was fine. 

[Regingrave-]

Hi there!

Sorry, wasn't checking the forum lately.
Let's take a look.
Have you made any modifications to the mission logic around recent updates?

We didn't do much to the code, especially for the dedicated server, so I have no obvious clues on what could be the cause, but I'll try to debug this.

I guess there is some logic to detect paratroopers through Complex Trigger events?

[Regingrave-]

12 минут назад, Barnacles сказал:

Thing is we have had missions that have not changed for years start to crash. We even wrote a brand new mission to celebrate the new Odessa map (with no complex logic in at all) and those crashed too.

Any clues on what mission events precede the crash, like the paratroopers mentioned above?
I'll need .mission files for the mission in the report and a simpliest mission you've got that still do crash. Plus, an .sds server config (you can PM them to me).

[Barnacles]

15 minutes ago, Regingrave- said:

Any clues on what mission events precede the crash, like the paratroopers mentioned above?
I'll need .mission files for the mission in the report and a simpliest mission you've got that still do crash. Plus, an .sds server config (you can PM them to me).

There problem was encountered almost as soon as the mission started, only some clients experienced it. So there was unlikely to be any paratrooper events.

I'll DM you the mission file

18 minutes ago, Regingrave- said:

Any clues on what mission events precede the crash, like the paratroopers mentioned above?
I'll need .mission files for the mission in the report and a simpliest mission you've got that still do crash. Plus, an .sds server config (you can PM them to me).

Oh can't DM the mission, so here it is

 

big-normandy-campaign-day-067.zip

[=DW=_BIRDD0G]

Hi @Barnacles, I probably don't know what I'm talking about, but shouldn't you send Day 066 vs Day 067?  Was Day 066 not a crash?

 

[Regingrave-]

13 часов назад, Barnacles сказал:

There problem was encountered almost as soon as the mission started, only some clients experienced it. So there was unlikely to be any paratrooper events.

I'll DM you the mission file

Oh can't DM the mission, so here it is

big-normandy-campaign-day-067.zip 590.15 kB · 0 скачиваний

It's a .msnbin file (a binary mission), I need a text file (.mission) to be able to edit and debug it.
You can use a cloud drive.

[Regingrave-]

Nevermind, found a way to open it anyways.