DCS Sim PostStart Freeze

I was away from DCS for a few months and recently came back and many of my missions won’t load. I freeze on the Sim PostStart part of the loading screen. I’ve found many posts about similar issues with multiplayer but nothing for single player.

Anyone else experiencing this or have any ideas? I run quite a few mods so I suppose one of them might be causing the issue. There was a theory that the Super Carrier module was causing some issues but I’ve tried removing it from some missions and that didn’t make a difference. I was kinda hoping that the update would help but I didn’t. Happens in both Open Beta and MT.

Mods always get me. Frustrating for several reasons. Anyway, that’s my best guess. I’ve given up on them for this. Or I create missions that allow me to easily ignore them. Depends on the situation.

You can try renaming your Saved Games folder (so you don’t loose stuff). DCS will re-create it. Then serially add in mods till it chokes.

SIDEBAR: If it it’s not freezing but taking a LONG…LONG…time to load sometimes the temp folder doesn’t get cleaned up. This happens when DCS exits. Or is supposed to.

This folder is in a different place. For me :


I check this every now and then. First time I discovered this it had 30,000+ files in it! Was taking forever. I deleted the folder (it gets rebuilt). and back to normal.


Well I looked in to the temp file thing and only had a couple files in there, but it was a good suggestion. I suppose I’m going to have to unload mods bit by bit. It seems it may just be taking a VERY LONG time vs actually freezing however I wanna know whats taking so long lol

Well the mystery continues, I’ve been testing random missions with mods and found one that wouldn’t work with only two mods. Removed one, no luck, and removed the other… and no luck… so now I don’t know what to do lol

I had a very similar behavior a couple of years ago and it turned out to be a failing SSD drive. Windows would boot normally, but when I went to load a DCS mission, it would take forever and sometimes fail. I can’t remember what finally tipped me off that it was the hard drive. Maybe a look at the Event logs.


Go to your Games Saved/DCS folder. Remove all you mods. See if you still have this problem… if you dont, put mods in one by one.
Also i wanted to ask, are you using MT ? For a bit my game kept crashing if i used MT.
Last suggestion is to use Skatezillas App to do a clean and repair.
Good Luck!


Sounds like my MSSA=0 bug.
Do you have MSAA turned off, by any chance? If so, set it to x2 and see if it helps.

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I’m getting the same thing, but only with the Supercarrier and the log always hangs up at being unable to load some deck crew “table.” I can fly online but I can’t fly any of my Tomcat/Hornet payware campaigns because of it.

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Very interesting Clutch that you are the second or third person to mention the Super Carrier in my reading and testing. I’ve tried removing them from some missions but it hasn’t seemed to help.

I’ll do some more experiments today.

Did some testing tonight, started with the SC and placed all my static aircraft. Loaded in just fine. Then I added in all the static vehicles, loaded in just fine.Then added deck crew and random static props, loaded in just fine. Decided to add a F-14 to launch and got a crash… though it didn’t generate a log. Had to restart DCS and when I reloaded the mission I got the Sim Poststar freeze… I don’t think it was the player controlled F-14, it almost seems it was closing the program down and reloading the mission. I wonder if I uninstall SC and reinstall if that would help. Gonna have to experiment more. Hope this leads to someone finding a solution.

edit: I did have MSAA turned on, also I was able to load other non SC missions just fine.


I tried the uninstall method and still had the same error while SC was uninstalled :joy:

For me the only surefire method is to not have any static deck crew or equipment in the mission. Occasionally I can get the mission to run after clearing fxo and metashaders2 folders or rebooting my entire system, but it’s not fool proof nor permanent. Sometimes if I wait just a little bit it will push through the Sim PostStart hang, but not always.

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It only takes 1 value to be off and DCS chokes…this is too far out there to possibly apply to the above situations but, while my coffee is brewing:

First, I do 99% of my missions in lua scripts along with generating various things in C# (desktop app). Yesterday I had the need to manually edit a lua table (a route) and wrote a C# function to remove a waypoint (wasn’t needed).

The form of the generated table was correct but due to the way lua works 1 waypoint was numbered (indexed) incorrectly. That caused the entire loading sequence to freeze, requiring Ctrl/Alt/Del + task manager to kill DCS. I only caught it cus, well, I just did it.

Looking at the mission lua in a text editor I could see the problem. DCS is a complicated beast. Perhaps fragile is a better word.

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So jross, are you thinking that failure is agnostic and it could happen with any module and mission, or that it might be AI F-14 related? Or both?

I wonder if Reflected has any thoughts on this, with his 3 x Tomcat campaign building experience?

Is is possible to get the suspect mission, to try it, and see what I can see. Do we think it’s a HB F14 + SC thing? I’ll try the latter in a few minutes.

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FWIW, I created the following mission:

CV-71 Super Carrier
Popped the HB F14 on the deck, cold start, as “Player”.
Nothing else in there, just those 2 objects, and no mods installed.
Loaded and started normally.

DCS is a finicky thing. I discovered a ways back, and this took a little digging, that if you have a bad miz file in the Missions folder DCS will not let you open anything in the mission editor, even a ‘good’ miz file.

The “Create Mission” button works but the “Load Mission” button does not. It’s like they do a quick scan of all the miz files when DCS loads (seems to only be the root ‘Missions’ folder, but may be deeper) and if any single one of them has the slightest blemish the ME won’t let you open anything.

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Before contacting Reflected about this issue, be sure that you are not using any mods.
He has recently posted a video where he states that he no longer offer support if people have mods installed while flying his campaigns.
He is not against mods, it is just that there is a great risk that they will create strange problems and they are difficult to troubleshoot.

He would rather work on his campaigns than troubleshoot errors caused by mods.

Happy Simming

Welp my worst fears have been confirmed. Removed all mods and tried running the same mission again, aaaaaand it hung. Waited approx 10 mins and still was hanging on Sim PostStart. It never actually crashes… but it certainly won’t load. Not sure where to go from here.

Kinda frustrated that I can’t use any mission with a carrier in it now… which is … most of mine lol

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I’ve been struggling as well. Every single time I think I’ve found a workaround, the next day the workaround stops working. I’ve removed mods. I’ve rebuilt my entire Saved Games. I’ve done slow repairs. I’ve done cleanups. I’ve built new missions. I had one workaround where running a newly built misison with deck statics works, and running all my bugged missions after that will work, but even that workaround didn’t last long. The only thing that works 100% is decks with no static crew or carts, or flying the bugged missions through my dedicated server.

So I can’t fly Raven One. Nor Fear the Bones. Nor Speed and Angels. Nor Zone V. When I can fly online I can’t get screens or videos because even .trk files with deck crew hang at Sim PostStart too.

I think…and this just a W.A.G…DCS changed something and they are intermittently saving the mission lua file with an error. I commented on this elsewhere recently (can’t find it right now); I’m constantly creating these ‘from scratch’ outside the mission editor and encountered a 2-day long issue - just like you all seem to be talking about.

Long story short, I thought it was me but the file, in my case, was missing the centerX (or was it centerY) component in in the mission lua, like so:

["map"] = 
    ["centerY"] = 331833.04514303,  <<<< This was not there
    ["zoom"] = 636322.18486008,
    ["centerX"] = -201009.0541927,
}, -- end of ["map"]

I hesitate to bring it up but my code never touches this value yet it was gone. DCS would hang about 1/4 way through…had to look in the log file to see a mention of “unable to create map camera” or something like that. Was a week or so ago. Makes sense as without both the X and Y values you can’t do anything (not many 1-dimensional camera conventions out there).

Anyway, if you’re really bored you can look at that file in a text editor (of the offending miz file). You’ll have to un-zip it (miz files are just ZIP files without a file extension).


Well that would actually be in line with my suspicion that once the game saves something basically corrupts the mission. I’m just wondering how this isn’t effecting more of the community. If its a mod interference it would have to be something common that we all have. It wouldn’t make sense that its a hardware conflict. It seems the issue creeps in on closing DCS, you can create and run a mission with deck crew no problem, until you close and try to reopen the mission.