What causes DynamicsFailedToConnect?

Office365 authentication with MFA or conditional access is no longer supported after June 8, 2021 — the regional Discovery Service was deprecated. The Dynamics 365 service URL is incorrect, or a proxy/firewall intercepts the request to the Dynamics server. OAuth configuration on the server is incompatible ('Office 365 auth with OAuth failed'). Unexpected server response ('An unsecured or incorrectly secured fault was received'). No organization found — wrong organization name or incorrect CRM regional identifier in the service URL

How do I fix DynamicsFailedToConnect?

If you see an error about MFA or conditional access, or the error mentions AADSTS50079: switch from Office365 authentication to Microsoft Entra service principal authentication — this is required after June 8, 2021 for MFA-enabled tenants.. To set up service principal authentication, see the ADF Dynamics CRM connector prerequisites documentation.. Verify the service URL is correct: for Dynamics 365 online it should be https:// .crm.dynamics.com (use the correct regional suffix if applicable).. If using a regional CRM URL (URL has a number after 'crm'), verify the correct regional identifier.. For other connection errors: use XrmToolBox to test the connection — if XrmToolBox succeeds but ADF fails, the issue is in the ADF configuration.. If error message contains '401 Unauthorized' with an Entra ID error, follow the guidance in the error to fix the service principal configuration.

High severitydata source

Power BI Refresh Error:
DynamicsFailedToConnect

What does this error mean?

ADF or Fabric could not connect to Dynamics 365 or Dataverse. After June 2021, MFA-enabled tenants must use service principal — Office365 auth is deprecated.

Common causes

1Office365 authentication with MFA or conditional access is no longer supported after June 8, 2021 — the regional Discovery Service was deprecated
2The Dynamics 365 service URL is incorrect, or a proxy/firewall intercepts the request to the Dynamics server
3OAuth configuration on the server is incompatible ('Office 365 auth with OAuth failed')
4Unexpected server response ('An unsecured or incorrectly secured fault was received')
5No organization found — wrong organization name or incorrect CRM regional identifier in the service URL

How to fix it

1If you see an error about MFA or conditional access, or the error mentions AADSTS50079: switch from Office365 authentication to Microsoft Entra service principal authentication — this is required after June 8, 2021 for MFA-enabled tenants.
2To set up service principal authentication, see the ADF Dynamics CRM connector prerequisites documentation.
3Verify the service URL is correct: for Dynamics 365 online it should be https://<org>.crm.dynamics.com (use the correct regional suffix if applicable).
4If using a regional CRM URL (URL has a number after 'crm'), verify the correct regional identifier.
5For other connection errors: use XrmToolBox to test the connection — if XrmToolBox succeeds but ADF fails, the issue is in the ADF configuration.
6If error message contains '401 Unauthorized' with an Entra ID error, follow the guidance in the error to fix the service principal configuration.

Frequently asked questions

Does this error affect multiple datasets at once?

If multiple datasets connect to the same data source, yes — all of them will fail until the source connectivity is restored.

Can this error be caused by a server migration or rename?

Yes — if the server name, database name, or connection string changed (e.g., during a cloud migration), Power BI still holds the old connection details. Update the connection in Power BI Desktop and republish.

Does this error appear in Power BI Desktop?

Sometimes — if you open the .pbix file and attempt a refresh, Desktop will surface the same connection error. This is useful for debugging without affecting the Service dataset.

Will the error resolve automatically once the source is back online?

Only if it was a temporary outage. The next scheduled refresh will succeed automatically. If the connection string changed or credentials expired, manual intervention is needed.

Source · learn.microsoft.com/en-us/fabric/data-factory/connector-troubleshoot-dynamics-dataverse