Error Code: CAA50021

Question

Hello,

Please i need your help on this.

When trying to login to Teams we get the below error message:

We couldn't sign you in. if this error persists, contact your system administrator and provide error code CAA50021

Answer 1

Hi @IBN

It seems related to Azure AD join and registration service.

We suggest you contact your admin to confirm if Mobile Device Management for Office 365 or Microsoft Intune services is enabled. If not, you may let admin login Azure AD admin login Azure AD admin center > Devices > Devices settings to check if “Users may register their devices with Azure AD” is enabled.

If the above suggestion is not working for you, it recommends you try to follow these steps to sign out of all my devices:

• Open Microsoft outlook and signed out of all accounts except for your primary account (the one you use to login to Teams with).
• Accessed my computer settings and selected "Accounts". Then I selected "Email & Accounts". Under the heading "Accounts used by other apps" I selected my primary account and clicked on "Manage". From there a separate webpage opens up (ttps://account.activedirectory.windowsazure.com/r/#/profile). On the right side of the webpage there is a link to "Sign out everywhere". Once you click on this link a message box pops up and requires confirmation that you want to sign out of all devices and selected yes.

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Answer 2

For me, logging in as admin, then renaming the user's Microsoft.AAD.BrokerPlugin folder to .old fixed the issue, as described here:

https://www.dell.com/support/kbdoc/en-us/000137758/microsoft-office-outlook-exchange-error-80090016-after-a-system-board-replacement