Slack breaks playback device on Windows 10, after troubleshooting with them, they point to Windows 10 as the issue

Hi Mara May,

I had to pause the troubleshooting, but what I found out until this morning is interesting.

As initially mentioned, I use a Dell XPS 15 (9500) with a Surface Headphones 2 and the latest version of Windows 10. Among the non-Microsoft startup services, I have a group of Dell Utilities, Intel Services, Killer Services, one Realtek Audio Universal Service, Thunderbolt Services and Dell's Wave Audio utility. I decided to disable and disregard the Services coming with software I know and am familiar with (Everything, Virtualbox, OpenVPN, etc.).

It appears enabling only the Killer Services caused the issues. When they are not launched either in Startup or while using the computer, my headphones do not lose one of their output format (blessed Stereo Mode).

Now, I don't know much about the Killer utilities and services coming on Dell machines, but... that is when it becomes interesting. There are four services under that utilities (too much if you ask me) and it seems like either the Killer Analytics Service or Killer Network Service caused the issue. I kept both disabled and enabled the other two: Killer Dynamic Bandwidth Management and Killer Smart AP Selection Service.

Like so, the behaviour was similar to pre-Huddle update from Slack. However, I said it became interesting. Launching the Killer Control Center requires those services running, so I did so to verify if a setting in the application was the culprit. There are Game modes in it after all. After rebooting and launching the Killer Control Center... I cannot reproduce the issue with my Surface Headphones 2 and Slack launching or being launched. I have both playback devices, "Headphones (... Stereo)" and "Headset (... Hands-Free AG Audio)" running stable. Even after reboot.

It is not clear yet if that is a permanent fix or an issue with the Killer Software or some issues with either services I initially found above. I would be curious to hear more from your team.

Kind regards,

Hello Mickaël C.,

I apologize for the confusion, what I meant was, does the same problem occur when using different headphones other than Surface? Anyway, thank you for the clarification.

We will be raising this concern to our internal team, but before that we need to make sure all basic troubleshooting in Windows have already been exhausted. Below are the steps, you just need to skip those you have performed already. I know and understand that you have done a lot of things already but please bear with us as we are trying our best to isolate this problem.

METHOD 1: Perform clean boot

This is similar to starting your PC to Safe Mode, this will isolate third-party services that may cause conflict to Windows.

• Please see link below and follow the steps: How to perform a clean boot in Windows

METHOD 2: Run System File Checker and DISM tool 

This will check and restore corrupted system files.

1. At the Search, Type Command Prompt.
2. Right-click on CMD > Select Open as Administrator
3. Type this command: 

   	dism.exe /Online /Cleanup-image /Restorehealth

Once completed, type another command to run system file checker.

1. On the same Command Prompt window.
2. Copy and paste this command: 

   	sfc /scannow

3. Wait for the command to finish, and then restart your device.
4. Test if it is now working.

METHOD 3: Test using Microsoft Teams

I'm not sure if you have tried this already but you can test using Microsoft Teams since they have similar environment with Slack.

• You can download Microsoft Teams through this link below: Download Microsoft Teams Desktop and Mobile Apps

METHOD 4: Create a new user profile

In the new user profile, everything must be in the default settings. This helps us determine if the issue is related to the user profile that you are currently logged on to.   

• To create a local user, please see link below and follow the steps:   Create a local user or administrator account in Windows
• The user name must be different than any others on the device.

If the above steps did not work, please help us with the following information:

• Aside from Slack update, was there any changes made to windows prior to the issue?
• What's the version of Slack running on this computer?
• We also need the OS Build. You can open WINVER to find it:
  • Press Windows Key + R.
  • At the Run dialog box, type WINVER.
  • Hit OK or Enter.
• If it's possible, could you try to test using other computer to see if the same problem persist?

Let us know the result and we will get back to you as soon as we can. 

Best regards,  Mara May MMicrosoft Community Moderator

Hello Mickaël C.,

Thank you for providing us with this information.

Can you confirm if this problem also occurs even if you are just using the built-in speakers or without your Surface headphones connected? For us to properly isolate the problem.

We look forward to your response. 

Best regards,  Mara May MMicrosoft Community Moderator

Hi Mara May,

Thank you for getting back to me. Yes, it is correct. If Slack is running or has been launch and completely closed/shutdown, the Playback device is not visible anymore in Windows. I have to either log off or restart the computer to see the Stereo mode.

That being said, we can skip all the updating, disabling, uninstalling drivers, and updating or factory resetting of headphones. And I'm sure I forgot some of the other standard steps :)

As for the Windows version, I am on the latest Windows 10 Pro version, 21H2. It is connected to company domain (fairly recently), but the issue was also present before it was connected.

See captures below.

Before Slack has ever been launched:

After Slack has been launched and even once Slack is closed:

Kind regards,

Hello Mickaël C.,

Thank you for reaching Microsoft Community Forums.

I hope you are doing well. I'm sorry to know what you have experienced with audio on your device. We really appreciate your time in bringing this concern to us. Let us work together to sort this out. Just to confirm I understand your concern correctly, the stereo mode only disappears when Slacks application is running, correct?

Please allow us to ask the following to get more clarity on this issue: 

• Is the problem also occurs when the headphones is disconnected?
• You've mentioned that this is a work computer, is it currently connected to your company domain/server?
• Can we ask the edition and version of Windows 10 running on this computer?
• To check, you can open WINVER: 
  • Press Windows Key + R
  • At the Run dialog box, type WINVER
  • Hit OK or Enter
  • It should show the Windows information.

I'm not sure if you have done this already, but you can try updating the audio driver for this device.

You may follow the steps on this link: Update drivers in Windows

We look forward to your response. 

Best regards,Mara May MMicrosoft Community Moderator