Low severityauthentication
Power BI Error:
AADSTS90126
What does this error mean?
Microsoft Entra ID (Azure AD) cannot infer the user's tenant from the supplied username on this debug-mode enrollment endpoint.
Common causes
- 1Sign-in attempted with a personal Microsoft Account (outlook.com, hotmail.com, live.com) on an endpoint that only supports work/school identities
- 2UPN suffix used during sign-in is not a verified domain in any Entra ID tenant, so the home tenant cannot be discovered
- 3Application uses the /common or /consumers authority while the flow requires a specific tenant ID or /organizations endpoint
- 4Guest (B2B) user signing in against their home tenant instead of the resource tenant, with no tenant hint provided
- 5Power BI Desktop / gateway configured with an account that was deleted, renamed, or migrated to a different tenant
How to fix it
- 1Sign in with a work or school account (UPN like user@yourcompany.com) whose domain is verified in the target Entra ID tenant — do not use @outlook.com / @hotmail.com / @live.com
- 2In the application or connection string, replace the /common authority with the explicit tenant ID or verified domain, e.g. https://login.microsoftonline.com/{tenant-id-or-domain}
- 3In the Entra admin center → Custom domain names, confirm the domain part of the UPN is listed as Verified; if not, add and verify it via DNS
- 4For Power BI dataset/dataflow refresh: open the data source credentials, remove the cached identity, and re-authenticate with an account from the workspace's tenant
- 5If this is a B2B guest scenario, ask the user to sign in with the format guest_upn#EXT#@resourcetenant.onmicrosoft.com or supply a tenant hint (login_hint / domain_hint) in the auth request