Having the exact same problem (C0000005 ACCESS_VIOLATION - ntdll) for the last week or so, if we find a solution I'll post it here.

FYI - Added rpt file and dmp files for 1.32RC as released today, still crashes with same errors.

I'm in the middle of reinstalling windows on an SSD just to see if it changes the ntdll.dll error - I tested on a virtual machine with Win7 32bit installed and found no problems with around 40 min testing. Could be 64bit related. Will update when finished downloading server and game files.

EDIT: approx 1 hour later, all looks promising and appears no crashes. Must have been a corrupted file(s) causing the problem.
Will give more feedback in a week when I get more time to test (after work)...

We narrowed our problem down to a corrupt profile (in the default folder in My Documents). After changing -profiles= to a new folder the server has been running 5 hrs straight. Previously we would get an ntdll error anywhere between lobby and 5 minutes in.

No way to know for sure, but the server profile was being shared with a client which may have been the cause.

Bhaz, it could have been a read/write error due to using the same - I did get warnings on the client when running the server with no server.cfg file; the file is locked or already in use sort of error, can't recall the whole thing now.

After only one successful run on Tuesday night for a couple of hours. all attempts to run the server again have failed with the same issue.

I tried -enableht on server and client, on client only, on server only and neither. all crash with same error, i thought this may have been an issue.

I have not changed any settings on the server in the last few days so am now out of options for a successful run. - have tried again after deleting profile as bhaz states above, no success.

i can Upload more rpt and dump files in case it may help more.

Same problem here.

I start the server and within 5min after loading the mission and playing, the server crashed with the same error. ntdll.

I will try a 32bit Windows or another system like linux. Hope anything works

Its a 64bit problem. On my 32bit Windows the Server runs fine for one hour ( edit: 3 hours] now.
I will test a fresh 64bit Windows too.

I have set a new partition with new install of 64bit windows. Same issue, server crashed after 5min.

So to solve the problem change the os to 32bit

I tested with new install of 64-bit. I have tried under 64-bit windows running a virtual machine (vmware) as 32bit windows and didn't get the crash (my only issue was firewalls and could not be seen on internet- only LAN).

Note: I have had crash even without a player joining the server.

A_Hoernchen - ntdll.dll is a 64bit OS file, it is the link library between 32bit programs and the 64bit OS.

Yeah i know. So why u do not install a 32bit windows on a new partition?

Its so easy to solve the problem.

Otherwise u must wait for a fix.

the issue with having to use 32bit os is the memory restrictions.
max is approx 3.25GB. the rest can be used with ramdisk programs, but a lot of work to fix something that was working before.

edited post above - 32bit did work in VM, no crash. tested again and ran for hours, just firewall and port forwarding got messed up so i couldn't see it on internet. my end so 32 bit does appear to function.

Still happening on new release of stable branch.

I am getting a similar error with the same DLL to on several servers. I've done the process of elimination and it crashes, even in vanilla when I just open arma3server.exe.

No change since Helicopters DLC went to stable.

I am getting this exact same issue. Like others, have completely deleted everything and reinstalled.

Each time after around 10-30 seconds, it crashes

Very frustrating as I am trying to develop a mod and this in my local dev enviroment. On another machine, I don't see this issue, but I cannot narrow down any differences at all.

Think I'm onto something,

the ntdll crash only happens if arma3server is launched with Steam open, completely exit Steam then run arma3server.exe. Once the server has completely started, steam can be relaunched.

thanks bhaz, worked for me, thanks for posting the workaround.

Indeed, thx a lot, bhaz! After pulling hair for a few months found this report and tried the workaround. Finally can play some good coop with friends!