CTD's during mission loads, freezes on MP server screen, total freezes on coalition select.

[MoleUK]

This is all on a fresh install of DCS, I nuked the old install to see if it would fix the problem but it had no effect. This is also using a fresh savedgames DCS folder, and a fresh install of Windows 11 after a reformat.

No mods are installed, everything is running vanilla. I am on Nvidia drivers 566.36, BIOS is on the latest update, chipset is updated. Cores are not parked. Tried with XMP disabled. The game install is whitelisted in windows defender, so is the savedgames folder.

Sometimes I am able to get into an instant action mission, sometimes it CTD's with no option to send off the error log.

Every time I bring up server select, it will freeze for long periods of time until the server list is completely refreshed.

On some servers I am able to get past coalition select, on others it will just freeze. Technically the game is still running, it is just running at less than 1 FPS. It will occasionally update the chat log etc. It appears to only be using 2 CPU cores when this occurs, both pegged to 100% load.

Logs and timestamped videos included.

 

CTD during instant action load.log freeze on MP join.log Able to get past coalition select on 4ya, but not contention.log

DX Diag included.

DxDiag.txt

Edited April 19 by MoleUK

[Gunfreak]

In singeplayer it works fine, but when I join my own dedicated server, I get to the point where I'm in the cockpit and the world is about to load in, however the game crashes instead.

[sleighzy]

3 hours ago, Gunfreak said:

In singeplayer it works fine, but when I join my own dedicated server, I get to the point where I'm in the cockpit and the world is about to load in, however the game crashes instead.

Please raise your own crash report and attach your DCS logs vs. using somebody else’s post, your issue may be completely unrelated. 

[MoleUK]

Incase it helps narrow down any sort of solution, the CTD's when they occur often happen during the 'terrain load' step.

When it's freezing on the servers coalition select, it's remaining connected to the server. Just at far less than 1 FPS. It will periodically update the chat feed with new timestamped messages. Seems to keep receiving/sending data from the server.

2 CPU cores remain locked at 100% usage while every other CPU core will just sleep with nothing to do. I have left it connected for over 10 minutes but it never recovers.

Edited April 19 by MoleUK

[MoleUK]

Also getting these events on some of the CTD's.

 

[ARM505]

Same. Recently, DCS dies on the 'loadTerrain' step of mission loading. One core is at 100%, everything else is idling. Repeat until the heat death of the universe (or I force close it from task manager). It hasn't always been on this step, but that's the most common. I've only managed to load into actual gameplay about 10% of the time. Pretty much unusable at the moment for me.

[MoleUK]

9 hours ago, ARM505 said:

Same. Recently, DCS dies on the 'loadTerrain' step of mission loading. One core is at 100%, everything else is idling. Repeat until the heat death of the universe (or I force close it from task manager). It hasn't always been on this step, but that's the most common. I've only managed to load into actual gameplay about 10% of the time. Pretty much unusable at the moment for me.

Glad to hear i'm not the only one at least.

Definitely crashes most often on the 'loadTerrain' step. Have had it get stuck there for a minute + and eventually recover as well.

[MoleUK]

On 4/23/2025 at 10:07 AM, ARM505 said:

Same. Recently, DCS dies on the 'loadTerrain' step of mission loading. One core is at 100%, everything else is idling. Repeat until the heat death of the universe (or I force close it from task manager). It hasn't always been on this step, but that's the most common. I've only managed to load into actual gameplay about 10% of the time. Pretty much unusable at the moment for me.

Any chance you are getting straight CTD's with no error message as well? If so are you on Win 11? If so can you check your c : users > username > Appdata > Local > Crashdumps and see if there are any .dmp's for DCS in there?

Apparently mine are pointing towards a 'double free' memory allocation error.

https://drive.google.com/file/d/1QAHF-34EpFHh_LpK3QDh_zW-vfyQe0Mu/view?usp=drive_link

Not having any crashes in other games, and DCS was running fine for me on the February and early March patches.

Edited April 26 by MoleUK

[MoleUK]

Another .dmp file from a CTD here: https://drive.google.com/file/d/1_DjC_IEtbo_Xs9X58RXHqX-mHXnVv-Tj/view?usp=drive_link

Edited April 26 by MoleUK

[ARM505]

On 4/23/2025 at 10:22 PM, MoleUK said:

Glad to hear i'm not the only one at least.

Definitely crashes most often on the 'loadTerrain' step. Have had it get stuck there for a minute + and eventually recover as well.

Hi, yes, I've also had it recover, and as you say, its not always that step, just most often at that step.

 

I am on Windows 11, but not getting any CTD's - if it does run, it runs reliably at least.

[MoleUK]

Well, I've run a memtest overnight with 0 issues. And ran a quick OCCT 1 hour run on both CPU + memory.

If there is a memory instability, I can't find it. That this only started happening after a Windows reinstall + a few DCS updates with no hardware changes makes me think it's either windows or DCS at fault here.

I will keep re-testing after each windows update, DCS patch and Nvidia driver update (just incase) to see if the issue resolves itself.

Until then, the game isn't playable for me anymore. 2.9.13 was fine.

Edited April 28 by MoleUK

[anormalpilot]

Thanks for this thread. I have exact the same problem and tried everything including punish my network carrier because i got baited into "peering problems". After several chats in ED Discord i do this (contention con probs). I'm really frustrated because i do weeks of bug fixing with no positive outcome yet. ED has to fix this issue. Luckily i read this issue on reddit.
SP is running flawless! Sometimes i can barely play on Growling but not play at Shadowreaper or Contention. Shadowreaper server are shorty located and stable  connection from german hetzner (17ms last hop). Every MP or SP Game play flawless in 4k or VR. This maschine is in heavy use because i have grown kids and i have harder SLA from them as from my customers ;-). I work also in IT, so basic knowledge seems no problem here. ED pls fix this

Hardware:
check my dxdiag below
AMD Ryzen 7 5800X3D
MSI B550-A Pro
64 GB Ram
2 NVME's
7900XTX Nitro+

FlightSIM setup FixedWing
Winwing Hotas (F-16+Shaker KIT + Throttle)
Thrustmaster MFDs (3)
F/A 18 UFC

FlighSIM setup rotary notr used last month so it think its not necessary

What I've done
CPU:
revert undervolting
disable virtualisation
check heat

RAM:
Disable XMP
Reduce Speed
Do testing with Windows and HCI Memtest and Passmark Memtest (advanced test took nearly 16 hours) -> 0 Errors

NVME
Testing
check smart
move to 2 second NVME
check heat

Mainboard:
reset all
disable virtualisation
check if last bios is installed
revert bios
run on low settings
run on stock settings
run on OC settings

Network:
disable DNS encryption
tried various german DNS, Google, Cloudflare, etc.
tried serveral VPN (Proton VPN, Mullad, Icvacy, Nord VPN, Express VPN) local or on Fr!tzbox
tried VPN protocolls (Wireguard, OpenVPN and propiertär)
do traceroutes to blame network carrier
try several network carriers (Deutsche Telekom, Vodafone, Telefonica)
disabled/enable IPV6
enable/disable all firewalls in windows
enable/disable all filter and firewalls in AVM Fr!tzBox
try to connect via WLAN
try to connect via Phones (Pixel 7, Galaxy S24, Galaxy S25) with several mobile providers
do wireshark for network carrier

AV:
run complete without AV
tried other AV
exclude DCS, Savefolder, Appdata temp DCS, SIMAPPPRO, TrackIr, Quest 3 stuff, HP Reverb G2 stuff, Mixed Reality

Windows:
check Event Viewer (found old unused OpenTelemetry Client *lol* -> disabled it -> run Windows with !0! errors)
do DISM, SFC
reinstalled and reset serverall drivers and check if all drivers are up2date
play also with swapfile
pause Bitlocker

Mouse:
changed DPI and polling rates
deinstall all software


Please fix it ED and thanks for the passion and support.
 

dcs.log DxDiag.txt

Ah forgot sorry. I expect since last big patch very long loading times on "Net SIM Post Start" on all servers. If it helps

Edited May 2 by anormalpilot
#1: forget something on windows list

[anormalpilot]

Is this Forum dead because there is no "investigation" statement?

Should i deliver more logs? Unfortunately seems that nobody check my logs?

I bought 56 DLCs at Steam for this game that i can't use in MP if i have want. Is DCS now a SP Game for users with this problem?

Should i open a ticket @ support?

[MoleUK]

On 5/2/2025 at 8:38 AM, anormalpilot said:

Thanks for this thread. I have exact the same problem and tried everything including punish my network carrier because i got baited into "peering problems". After several chats in ED Discord i do this (contention con probs). I'm really frustrated because i do weeks of bug fixing with no positive outcome yet. ED has to fix this issue. Luckily i read this issue on reddit.
SP is running flawless! Sometimes i can barely play on Growling but not play at Shadowreaper or Contention. Shadowreaper server are shorty located and stable  connection from german hetzner (17ms last hop). Every MP or SP Game play flawless in 4k or VR. This maschine is in heavy use because i have grown kids and i have harder SLA from them as from my customers ;-). I work also in IT, so basic knowledge seems no problem here. ED pls fix this

Hardware:
check my dxdiag below
AMD Ryzen 7 5800X3D
MSI B550-A Pro
64 GB Ram
2 NVME's
7900XTX Nitro+

FlightSIM setup FixedWing
Winwing Hotas (F-16+Shaker KIT + Throttle)
Thrustmaster MFDs (3)
F/A 18 UFC

FlighSIM setup rotary notr used last month so it think its not necessary

What I've done
CPU:
revert undervolting
disable virtualisation
check heat

RAM:
Disable XMP
Reduce Speed
Do testing with Windows and HCI Memtest and Passmark Memtest (advanced test took nearly 16 hours) -> 0 Errors

NVME
Testing
check smart
move to 2 second NVME
check heat

Mainboard:
reset all
disable virtualisation
check if last bios is installed
revert bios
run on low settings
run on stock settings
run on OC settings

Network:
disable DNS encryption
tried various german DNS, Google, Cloudflare, etc.
tried serveral VPN (Proton VPN, Mullad, Icvacy, Nord VPN, Express VPN) local or on Fr!tzbox
tried VPN protocolls (Wireguard, OpenVPN and propiertär)
do traceroutes to blame network carrier
try several network carriers (Deutsche Telekom, Vodafone, Telefonica)
disabled/enable IPV6
enable/disable all firewalls in windows
enable/disable all filter and firewalls in AVM Fr!tzBox
try to connect via WLAN
try to connect via Phones (Pixel 7, Galaxy S24, Galaxy S25) with several mobile providers
do wireshark for network carrier

AV:
run complete without AV
tried other AV
exclude DCS, Savefolder, Appdata temp DCS, SIMAPPPRO, TrackIr, Quest 3 stuff, HP Reverb G2 stuff, Mixed Reality

Windows:
check Event Viewer (found old unused OpenTelemetry Client *lol* -> disabled it -> run Windows with !0! errors)
do DISM, SFC
reinstalled and reset serverall drivers and check if all drivers are up2date
play also with swapfile
pause Bitlocker

Mouse:
changed DPI and polling rates
deinstall all software


Please fix it ED and thanks for the passion and support.
 

dcs.log 206.11 kB · 2 downloads DxDiag.txt 99.7 kB · 2 downloads

Ah forgot sorry. I expect since last big patch very long loading times on "Net SIM Post Start" on all servers. If it helps

Hm, I do have the same processor as you. I am also seeing the same long pause on 'net sim post start' when joining any server.

Are you seeing the same freeze on coalition select when trying to join contention/heatblurs cold war/shadowreapers? I have managed to get past it ONCE, by changing the DCS process priority in task manager over and over gain.

I suspect windows is deprioritizing the DCS process or getting something wrong in the scheduler, and DCS ends up getting clogged up on 1-2 CPU cores during loading screens and menu screens.

[anormalpilot]

#1 Contention:
Started DCS change process to real time, CPU doing something on 1 proc and Ram usage increasing from 800mb to 14Gb in maybe 10 seconds. Was not able to alt tab into game. Changed process to normal, wait 1 minute, change process to low, alt tab possible, DCS vanish.
During the NetSimPostStart the Status changed from running to inactive

Also tried this on shadowreaper same issues and not normal behavior of DCS. CPU1 is running crazy on 100%, rest is idle, make ~23% cpu usage at all.

next behavior
If i try to grab DCS via mouse instead of alt tab -> left click on symbol -> right click on DCS, it opens for every click another DCS process stuck with ~x0.000k ram.

Outcome:
priority change doesn't help -> but thanks mate.
 

dcs_#1.log

[MoleUK]

15 hours ago, anormalpilot said:

#1 Contention:
Started DCS change process to real time, CPU doing something on 1 proc and Ram usage increasing from 800mb to 14Gb in maybe 10 seconds. Was not able to alt tab into game. Changed process to normal, wait 1 minute, change process to low, alt tab possible, DCS vanish.
During the NetSimPostStart the Status changed from running to inactive

Also tried this on shadowreaper same issues and not normal behavior of DCS. CPU1 is running crazy on 100%, rest is idle, make ~23% cpu usage at all.

next behavior
If i try to grab DCS via mouse instead of alt tab -> left click on symbol -> right click on DCS, it opens for every click another DCS process stuck with ~x0.000k ram.

Outcome:
priority change doesn't help -> but thanks mate.
 

dcs_#1.log 224.92 kB · 1 download

Yeah unfortunately it's only worked the once for me.

I have noticed occaisionally it's listing DCS as in 'efficiency mode', despite the active power setting being high performance. Even manually setting the DCS process to 'high priority' in task manager doesn't necessarily fix it.

It's why I think it's something to do with windows flagging the DCS process incorrectly in some way. If you enable SMT, you will go from 1 core at 100% while the game is frozen, to 2 cores locked to 100%. And it will seemingly stay that way for long periods of time. When I connect a server like HBCW or Contention, the two CPU cores will stay locked to 100% the entire time i'm frozen, till i'm kicked from the server due to a login timeout.

Edited May 5 by MoleUK

[Kanelbolle]

You have a error in the log that points to DCS not having access to a temp folder. This might ocure if DCS is runned in "Run as Administrator" (Don't run DCS in admin mode) or other user account changes have made permissions to the folder change.

Try to delete this folder

C:\Users\MoleU\AppData\Local\Temp\DCS\

 

On the cores not being used, i have no experiance with AMD, but someone told me the Game bar has to be active for AMD CPU's to schedule right.. Also you can look in to "Process Lasso" or other software that can forces cores to be used.

[MoleUK]

1 hour ago, Kanelbolle said:

You have a error in the log that points to DCS not having access to a temp folder. This might ocure if DCS is runned in "Run as Administrator" (Don't run DCS in admin mode) or other user account changes have made permissions to the folder change.

Try to delete this folder

C:\Users\MoleU\AppData\Local\Temp\DCS\

 

On the cores not being used, i have no experiance with AMD, but someone told me the Game bar has to be active for AMD CPU's to schedule right.. Also you can look in to "Process Lasso" or other software that can forces cores to be used.

I don't currently have the game running as admin, but I have noticed reference to the temp folder in the logs. Might be related to this bug?

Just tried deleting the DCS temp folder but no change, still hanging on coalition select with 2 cores pegged at 100% usage. At least when it doesn't CTD during load.

Game bar is necessary for the AMD CPU's that have two CCD's, but mine isn't one of those. I still think either it's a scheduling problem, or something is causing a loop in the main sim thread, which will then peg 1-2 cores (depending if SMT is on or not) and the other cores remain idle since nothing is really being rendered, so no work for the rendering threads. Just a guess though.

[cfrag]

18 minutes ago, MoleUK said:

Might be related to this bug?

I strongly suspect that these are not related. The bug that is discussed in that thread is that DCS.getMissionName in single-player erroneously returns the name "tempMission" instead of the correct mission file name. It does not mean that DCS is accessing a temp folder, just that the name of the mission is incorrect. That bug does not implicate any locations on your storage. 

[MoleUK]

I have now moved from Windows 11 24H2, to Windows 11 23H2. It has fixed all issues. No CTD's, no freeze on coalition select, no huge freezes on server select menu. No lockups on main menu. The mission loads (to both MP and SP are now extremely fast, no hanging on terrain load or net sim post start for minutes at a time.

My DCS install, BIOS etc all remain the same as they were on 24H2. My overclocks/undervolts and XMP etc are all re-enabled, all SSD's and hardware is the same.

So, in my case it was the very latest version of 24H2 that was causing all the issues with DCS. Potentially it could have been a bad install, but given some of the issues other users are seeing I suspect 24H2 has some new problems with DCS that have appeared in the last month or two.

For now I will try and keep my system locked to 23H2.

On 5/4/2025 at 9:49 PM, anormalpilot said:

#1 Contention:
Started DCS change process to real time, CPU doing something on 1 proc and Ram usage increasing from 800mb to 14Gb in maybe 10 seconds. Was not able to alt tab into game. Changed process to normal, wait 1 minute, change process to low, alt tab possible, DCS vanish.
During the NetSimPostStart the Status changed from running to inactive

Also tried this on shadowreaper same issues and not normal behavior of DCS. CPU1 is running crazy on 100%, rest is idle, make ~23% cpu usage at all.

next behavior
If i try to grab DCS via mouse instead of alt tab -> left click on symbol -> right click on DCS, it opens for every click another DCS process stuck with ~x0.000k ram.

Outcome:
priority change doesn't help -> but thanks mate.
 

dcs_#1.log 224.92 kB · 4 downloads

^ See above mate.

While I can't say moving to 23H2 will solve all your problems, it did mine. Doing so does mean deleting everything on the windows drive, so it's not a trivial. And potentially you will need to prevent it from auto-updating back to 24H2.

Everything running great for me atm tho, will keep updating and reinstalling all my old software and see if the issue returns.

Edited May 10 by MoleUK

[MoleUK]

Incase it does help anyone else:

I've been on Win 11 24H2 since Oct last year, but due to a screwup on Microsofts end anyone who installed 24H2 via USB Media creation in October/November were stuck on that particular build and couldn't update. The only way to fix it was to completely reinstall 24H2. I kept putting this off, as DCS and all other games were working fine and I didn't want to delete everything on the boot drive.

I took a break from DCS in Febuary/March (when everything was still working fine), and I finally finally relented and totally reinstalled 24H2 so I could keep getting security updates at the beginning of April. I also did this install via USB Media creation.

Whatever went wrong for me was in that recent install of 24H2, whether just a bad windows install or something else. But the ONLY app/game that seemed to have issues with that new install of 24H2 was DCS. Everything else worked fine. Which to me would point towards a specific issue in the latest versions of 24H2 rather than a bad windows reinstall.

And switching to 23H2 didn't just fix the freezing/CTD's, it also appears to have fixed the long load times. So it may be a wider problem, idk.

Edited May 10 by MoleUK

[anormalpilot]

Thanks i will give it a try. I'm on 23h2. Will report later.

[anormalpilot]

Now i'm confused. I updated via ISO to Windows 11 24H2 this night.
I connected to shadowreaper syria with no gear activated (NO HOTAS, NO MFD, NO TrackIR etc.) without any problems.
This evening i will give it a try with all my gear and maybe VR.

My problem seems solved and i can *indredibly* fast connect to shadowreaper.
I attached my last DCS verbose log and DXDiag if it helps.

But now i'm totally confused because MoleUK stick on 23H2.

dcs.log DxDiag.txt

[MoleUK]

33 minutes ago, anormalpilot said:

Now i'm confused. I updated via ISO to Windows 11 24H2 this night.
I connected to shadowreaper syria with no gear activated (NO HOTAS, NO MFD, NO TrackIR etc.) without any problems.
This evening i will give it a try with all my gear and maybe VR.

My problem seems solved and i can *indredibly* fast connect to shadowreaper.
I attached my last DCS verbose log and DXDiag if it helps.

But now i'm totally confused because MoleUK stick on 23H2.

dcs.log 313.53 kB · 0 downloads DxDiag.txt 103.22 kB · 0 downloads

Hah, seems the main thing might just be a fresh Windows reinstall. Though my install was only a month old, a reinstall (via ISO) still did the trick.

A full windows install can nuke/delete a lot of things. But I have reinstalled all the previous mods/third party software and all the performance tweaks and it's all still fine atm.

So I have no idea what problem it's fixing, but at least your issues are fixed as well now.

Edited May 13 by MoleUK