to Teams blocked by Conditional Access only in Preview-Mode




we want to enable Teams Public Preview Mode by configuring the Teams Update Policy for a few users. During our first test we have noticed that users can no longer login to MS Teams in Public Preview-Mode. If they disable Public Preview-Mode they can immediately sign-in again.


In Azure AD Sign-In logs we see that the sign-in is blocked by conditional access.


  • Access policy does not allow token issuance teams
  • Sign in error code 53003


Anybody experienced similar problems and know a workaround? I suuspect that Teams is using an unkown App-iD in Public Preview-Mode or something like that.


2 Replies

Hi, Could you give a little bit more back info?

Like: From which devices are you testing? What did you configure in the conditional access rule? MFA or only allow teams from managed/compliant devices?


You could also compare the azure ad sign-in log with the one that does not work to check for differences

We also have teams in preview mode with a lot of conditional access rules configured and that is working without any issue?

hi. I have same problem.I can not enter the Teams after about April 2. The error code is 53003. Now I am abroad and I asked a relative in the homeland to enter with my email and she entered, but I could not enter. Maybe you can help me, I do not want to miss lessons. thank you in advance.