Citrix Receiver – AuthManSvr.exe using high CPU on client workstation

So, last year I was informed by a co-worker that he was having some issues with Citrix Receiver on his computer.
He was using a Microsoft Surface, and was experiencing that the Surface, was getting noisy, and battery drained in no time.
Now, obviously, this was due to something using alot of resources on his Surface.
He had checked this himself, and found that the issue was coming from Citrix Receiver.
When machine was getting noisy, etc, he just killed Receiver, and all was good.

But that is a low cost workaround, at best, so I decided to do some more digging regarding this.

He was the only one of my co-workers that had reported this issue to me.
First step was to look for what is different from his computer, and others at the office.
The difference seemed to be that he was running Windows 10 Enterprise, while others did not use Enterprise.
Differene nr 2 was that he used Direct Access.
So, I decided to reinstall my own Surface with Windows 10 Enterprise, and activate Direct Access for myself.
After reinstall, deployment of receiver with SSO enabled and enabling Direct Access I did some testing.

I got the same problem as my co-worker, high CPU from Receiver, drilled down on the process level, and found AuthManager service to be the sinner.
Next step, disable Direct Access, this resulted in no change, still high cpu, noisy fan, and short batterytime as a result.
Also tried with different versions of receiver, 4.3>4.6.
So, this concludes to Windows 10 Enterprise as the real sinner.

Opened a Case with Citrix during the troubleshooting.
Created some dump from receiver, sent to Citrix, and waited for feedback, my Citrix contact also tried reproduce the issue with no luck.
After a while the response from Citrix Dev came.

They concluded on issues whit the Smart Card dll in Windows and wanted med to check by doing this:

«navigate to “C:\Windows\System32\Winscard.dll”. Rename the file (winscard.dll.old), reboot the machine and check.”

You may need to take ownership on this file before you can rename, just remember to write down the permissions before the change, for restore later.

The results?:
1. Renamed WinScard.dll on my Surcace with Enterprise. Rebooted. AuthMangere is now normal
2. Restored WinScard.dll to the original name,rebooted. Problem comes back.


So the issue definetly comes from Windows 10 Smart Card dll.
Now this fix from Citrix works if you are having this issue, but in my eyes it’s not a permanent fix.
Who knows when the Smart Card dll get changed during windows updates etc.
Also, renaming OS files is never a good solution in the long run.
I informed Citrix that a permanent fix was still needed, but case got closed for now.

Now beeing a member of a Citrix Slack channel, someone reached out to me with the same issue.
I informed them on the fix from Citrix, and just recently got a meesage saying it worked there aswell.

Now if someone else is experiencing this, I prompt you to report the issue to Citrix, so they can see this is not an isolated incident.
When reporting, refer to casenr: 72196652, which is my original support case at Citrix.

Hopefully this gets resolved in a later update on the Receiver side, or the OS side.

 

Senior System Consultant at Serit IT Partner Møre AS, localized in Møre og Romsdal, Norway. Primarily focus on virtualization and datacenter solutions. Specialized in Citrix XenApp/XenDesktop, certified CCE-V.

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