"The paramter is incorrent" error in new Teams client (VDI)

I have the exact same problem with a client, I've tried erasing all that has to do with teams and reinstalling but still get the same error, the old teams works fine. MTU42 

MTU42 

Hey Guys,

I've been trying to debug this this for WEEKS. At some point I certain that I've had surfed EVERY page on the web, but nobody came up with a fix that solved this problem in my envoiroment . Finally, just today, I managed to solve the problem for good.

My Users got exactly this error when tying to start the New Teams Client:

We are using a Remote Desktop Session Host envoiroment (RDSH, a.k.a. Terminalserver, operating on Windows Server 2022 (but I had the same error prior the InPlace-Upgrade on Server 2019), however we are NOT using FSLgix, like a hundred other buddys i found out there on the web, trying to solve this problem (apperantly they solved their problems by upgrading FSLogix).

My solution may sound stupid, but works 100% for two ADs that i manage. So... "If it's supid, but it works: It ain't stupid" 😉

In the end, the problem was caused by a GPO. I was able to solve the issue by adjusting this user-trageted GPO:

User Configuration > Preferences > Control Panel Settings > Internet Settings > Internet Explorer 10 > (Tab: General) > (Section Browsing history) > Settings. Here, my users hat an alternative path for their TEMP-Files:

I updated this setting by removing the path and leaving the setting blank:

I saved the GPO and as soon as my users logged in, the New Teams Client started like nothing ever happened.

Surely, I didn't go for this setting in the first place, but I found out that RDSH-Users without GPO could start the New Teams Client, users with a GPO assigned could not. So I narrowed it down, by cloning my PROD-GPO, assigning the Clone to a test user. Then I removed GPO-settings from the Clone bit by bit until I had a working New Teams - until finally, I narrowed it down to THIS specific setting.

I have no idea, why this setting is responsible for causing the problem, but after weeks of frustration, I only care for the problem to be finally fixed. All my >250 RDSH-Users are able to use the New Teams Client now.

EDIT: For everyone who is facing the same problem: My problem might have been caused in the first place by a registry setting, that we had in one of our user GPOs. This Registry-Setting is basically the same like the Internet Explorer 10 setting mentioned above. So if your system has the same issues like mine, it's work checking this setting too: User Configuration > Settings Registry

Iam still facing issues with the Teams UWP app shortcut in startmenu.

W2019 RDSH. FSLogix 2210 HF4 with correct exclusions in redirection.xml. Internetoptions in place like described by ehm-weh. No redirection of INetCache in place. No Citrix UPM. NTFS security settings on C:\Programs\WindowsApps are correct (same as in a know-good environment). AllowAppInstallation etc. has been set (via GPO and via Registry prior Teams Installation).

Iam still getting ms-teams.exe: parameter is incorrect on all existing user profiles when using the UWP shotcut in the startmenu. Also on new user profiles. Also after a complete uninstall and reinstall of Teams. Teams on RDS is a real pita... 

Any ideas? I sure can place an additional shortcut into the startmenu / on the desktop which points to ms-teams.exe and it will work fine. Thats kind of a workaround. BUT: That faulting UWP shortcuts also stays in the startmenu. My guess is that something goes wrong when the Teams app registers itself, but I cannot seem to get my hand on "why".