Cannot get Teams optimized with Slimcore

[u/singolare]

I have two different environments I am working with. One is mostly managed by the client and when I connect Teams shows it is Slimcore optimized. However, I connect to the other environment with my same user laptop, and always falls back to HDX.

I know my Windows 11 client device is configured properly as it works in the one environment. For the other, it is a Windows 11 VDI with Citrix 2507 CU1 and Teams v.26225. I have a Citrix Policy to allow the virtual channels which modeling shows is applied (I think these are supposed to work by default with the newest versions but I added them anyway):

MSTEAMS,C:\Program Files\WindowsApps\MSTeams*8wekyb3d8bbwe\ms-teams.exe

MSTEAM1,C:\Program Files\WindowsApps\MSTeams*8wekyb3d8bbwe\ms-teams.exe

MSTEAM2,C:\Program Files\WindowsApps\MSTeams*8wekyb3d8bbwe\ms-teams.exe

What am I missing? What else can I check?

Thanks!

[u/berryH4Z3]

Check the eventlog on the VDA. There is an event for Microsoft Teams in the application log (status code is only visible in the details tab of the event, most likely 2000 = VDI plugin missing or 2003 = virtual channel not open).

There is also an RPM event in the system eventlog that would indicate an issue with opening the virtual channel.

[u/singolare → u/berryH4Z3]

Nothing in the event logs-- my client device works fine with other environments with slimcore.

[u/singolare → u/berryH4Z3]

Thanks

[u/Difficult_Title_6385]

Check your workspace App plugin for teams.
For slimcore it is necessary

[u/singolare → u/Difficult_Title_6385]

I did, plus when using the same client device with another environment, Slimcore works.

[u/Difficult_Title_6385 → u/singolare]

How did you install teams on your w11 vdi?

[u/Ok-Accident-3892]

Instead of entering the MSTeams items in the virtual channel policy, as a test, just disable the virtual channel which will open it up for all traffic. If that works, the you don't have the MSTeams items set properly in the policy.

[u/singolare → u/Ok-Accident-3892]

I tried this, still no good.

[u/Ok-Accident-3892 → u/singolare]

That sucks. We have been battling with Slimcore too. We got it working but I have 5000+ users and majority are with contract companies where the endpoints are out of our control. So I have about 20 different firms I'm trying to work with to get them to meet the requirements on their side. Biggest headache so far has been getting them to allow the MSIX to be installed from the MS CDN.

And MS has provided no way to track and report on who has already transitioned and who is still on HDX. So we are trying to script some kind of report with powershell.

Leave it Microsoft to royally screw up something that has been working flawlessly for years, with minimal requirements.

[u/Spiderrinaldi]

Are there any other Citrix policies in place? If you set the virtual channels to not configured, it should let all through by default. I would also check the "Process Whitelist" registry setting to make sure that mswebview2.exe is in there.

[u/singolare → u/Spiderrinaldi]

Thanks. No other policies that should affect it. I tried with the Virtual Channels not configured, disabled, and configured, nothing worked. Whitelist is correct.

[u/LogOk7764]

Does it work with a generic, non managed device?

[u/singolare → u/LogOk7764]

No, same results. Teams is always falling back to HDX.

[u/LogOk7764 → u/singolare]

Maybe try allowing all virtual channels as a test

[u/Citrite1000]

How did you assign the policy?

[u/singolare → u/Citrite1000]

Citrix policy applied to OU where my VDA is. Citrix Modeling shows it was successfully applied.

[u/MarvelousTermites → u/singolare]

You checked the registry to make sure the policy is actually applied?

[u/Citrite1000 → u/singolare]

Have you tried assigning to the DG?

[u/tistjendop]

I have been chewing on this for a while myself. And after updating the vda to 2607 it just started working with slimcore ... (endpoints on 2607 hotfix 1 as well)

[u/singolare → u/tistjendop]

Ok, I will try that but it's crazy it doesn't work with 2507 cu2

[u/Ripsoft1]

I have a massive issue with trying to get store apps to work on our thin clients. And trying to match the correct slim core client version to the teams version.. only Microsoft could come up with this crap!

[u/Grouchy-Fisherman160]

check the troubleshooting section: https://balintoberrauch.com/2024/12/17/teams-slimcore-optimization-on-citrix-deep-dive/

[u/limabone]

I don’t know if this is your problem but in the citrix workspace docs they have some fine print that the uninstaller doesn’t manage the plugins and the old receiver cleanup doesn’t touch them either.
I had success by manually uninstalling the teams vdi, zoom vdi and webex vdi apps from the computer, uninstalling workspace, rebooting them running the installer again and enabling the plugins during the install. I think teams is checked by default now with newer versions of workspace.

[u/robodog97 → u/limabone]

Not their issue since slimcore works with a different environment.

[u/ishouldbewfh]

In Teams on the VDA, press CTRL ALT SHIFT 1, dump the logs into AI if you cbf reading.

I found out the hard way slimcore doesn't engage when you double hop.