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Windows Server 2016 DWM process crashing


pacerra529

Question

I am in the process of testing Windows 2016 with the ServerVDI option.  Everything works great for a few days but after about a week the dwm.exe process crashes and calls out dwmcore.dll.  When this occurs the screens go completely black or flicker black.  This issue occurs with multiple endpoints. Sometimes the desktop will recover but other times it will require a reboot.  I was able to capture the dwm.exe dmp file but it didn't really give me too much information.  The only similar issue I saw online was a black screen during login.  I can't reproduce the issue at will but it tends to occur a few days after using the virtual desktop and most of the time when browsing the web.

 

Components: XenDesktop 7.15 cu2, PVS 7.15 CU3, VDA 7.15 CU2(Also tested with VDA 18.11)

PVS using write cache 512MB non-persistant

Desktops : OS Windows 2016 with ServerVDI option(DesktopOS vda)  2 cpu and 4GB RAM

 

Info from dmp file for dwm crash

 

In dwm.exe.13112.dmp the assembly instruction at dwmcore!MilInstrumentationHandleFailure+5c530 in C:\Windows\System32\dwmcore.dll from Microsoft Corporation has caused an unknown exception (0xc00001ad) on thread 4
 

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I saw this problem when I was testing 2016 a while back.

 

I have physical HP servers.  They have an onboard GPU and I have installed an nVidia quadro card in them.  When I had the BIOS GPU settings set to Auto, it would cause this issue after a few days.  This setting is the one that allows you to enable/disable onboard and external GPUs.

 

I don't have anything to back it up, but I believe it had something to do with the GPU running out of memory.  It was hard for me to tell since my first indication was that I couldn't do anything with the machine.  Upon rebooting, I saw DWM crashing every time a new user tried to log in...

 

I really hope that helps.  I understand how frustrating this problem is!  I know it doesn't translate exactly to your environment, but I hope it gets you close to the solution!

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Thanks for the reply. Yes it's very frustrating and it's holding up my project. I am trying to migrate Windows 2008 R2 desktops on the same exact hardware and Citrix versions. You are probably onto to something though, it seems like the video memory is not working correctly. Windows 2016 demands more than 2008. The backend hardware is EMC VxRail hyperconverge. I might try moving the virtual desktop to a different VMware cluster. 

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We have experienced this issue with Windows 10 but our issue was caused by a memory leak from Ivanti Application Control programme . This caused the page file to fill to its maximum file size and then DWM would crash as it ran out of resources. We also used to experience the flashing desktop just prior to the DWM failure but this was helped by increasing the amount of video memory allocated to each VM to 128MB's. We are still not sure why the Application Control agent is leaking memory but we have a support call open between Ivanti and FSLogix (which we also use) to see if one is causing the other issues. Nothing confirmed yet either way, but we removed the Application Control agent from the PVS build and straight away the disconnections stopped. 

The affected vm would then most of the time refuse to reconnect to the users session but the VM itself would be ok so you could still view the users session through the hypervisor console if needed. 

 

We are running the same Citrix software as you except we are using CU3 on both VDA and PVS 7.15 agents within the Windows 10 build. 

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Just to add another voice, we are having similar dwm.exe events.

 

HPE Servers

Vmware ESXi 6.7

Nvidia vGPU

Win 2016 VMs

Citrix VDA 1903

FSLogix

Ivanti Application Control

 

Controlup shows Pagefile is at 100% on the affected VDAs.

Users unable to connect, coinciding with the dwm events

 

We are at the beginning of our troubleshooting process and found this thread.

 

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Bringing this back from the dead for an update...I may be experiencing a similar issue to this on my Win10 VDI, have been having reports of random black screens then user getting kicked out of their session and unable to get back in.  I found some evidence of dwm.exe crashing in the event logs, and we are using WEM.  We're running a 2GB page file on the VDI's, and I did have memory management enabled in WEM so the pagefile size was generally pretty high despite having 8GB ram available to the user in the VDI.  I have disabled the memory management to see if that does help with the issue.

 

Were there any updates to your original issue?  Did disabling the memory management seem to resolve this long term?

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