Teams desktop app for a colleague on their personal device at home with error CAA20002 + AADSTS80014

Brass Contributor

Dear Teams gurus,


have you ever come across this error?  Basically its a 3rd lockdown here in the UK so we are all back to remote learning.

One of our teachers is experiencing a most peculiar problem:


They can log into teams for our domain using the web version

however the desktop app on their Windows10 machine gave them an error:


error code: 80090016

server message:  Keyset does not exist.


I searched "wamerrors  80090016 Keyset does not exist".  and apparently this was to do with the TMP module on the Server, which seems unlikely to me as:


We are connecting to M365 and

The computer the person is using is not a school computer but their own computer instead just logging into teams.


I had originally asked them to sign out and when they sign back in to untick the box to "allow my organisation to administer this device" and to click the option for "This app only"  


however that has not worked.

I then asked them o uninstall and reinstall and the person managed to log in for a few moments only to then get the latest error  (which is now different):


error CAA20002 

Server message: AADSTS80014 Validation request responded after maximum elapsed time exceeded.

The person can still log in via Teams Web, however the app now does this.


My next step was going to be closing teams completely then clearing the cache, however they are currently teaching using Teams web.

whilst i wait for them i thought i would ask fellow Teams admins in case anyone has come across this.


I have looked at azure AD and their settings look the same as other users and their private device isn't listed there.


Has anyone ever come across this and are you able to offer any pointers?

Thank you for any help you can give.


2 Replies



Clear cache and maybe reinstall Teams is a good idea.
Clear the Microsoft Teams Client Cache (


AADSTS81004 indicates that there is some problem with the SSO.


AADSTS81004 DesktopSsoIdentityInTicketIsNotAuthenticated - Kerberos authentication attempt failed.
Azure AD authentication & authorization error codes | Microsoft Docs

@Linus Cansby 


Thank you very much for this.


Unfortunately i am not going to get to try it now as the person was in a hurry and another colleague had to take it  up in my absence as i had to do something else.


I had seen other posts suggesting clearing the cache and that was going to be my next step but it wasn't to be i guess.


I hope this helps others in the same pickle.


Many thanks for your kind help.