DataFlow

Hi  LuisMartins ,

Could you please make sure that you have configured gateway for your database and you could check if the credential is correct in your gateway and be same withe the credentials in your dataflow.

https://community.powerbi.com/t5/Service/DataFlow-Add-Data-Source-MySQL-Issue/m-p/677020

https://community.powerbi.com/t5/Service/Changing-Data-Gateway-on-an-existing-DataFlow/m-p/2329349

You can also check the following:

1. Since it's a Windows authentication, please check if your account has enough permission. 
2. One DataFlow can only use one Gateway. Please don't change the gateway when you add more entities. 
3. Check the entered URL, username and password, you will also receive this error message if you enter the wrong one.
4.   Another reason could be wrong source selection like SharePoint Online List source & SharePoint List source.

This is the related document, you can view this content:

https://community.powerbi.com/t5/Service/Invalid-credentials-when-trying-to-connect-to-data-source-to/m-p/803451

https://community.powerbi.com/t5/Service/PowerBI-Dataflow-invalid-Credentials/m-p/820747

https://community.powerbi.com/t5/Service/Invalid-Credentials-When-Using-Azure-Data-Lake-Storage-Gen2/m-p/2060554

https://www.reddit.com/r/PowerBI/comments/fd4wa9/cant_connect_dataflow_to_azure_sql_database/

Best Regards,

Liu Yang

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