Connecting to sharepoint

Hi AhmedShalaby , I think your credentials are cached in the datasource settings . 

can you go to the pbi desktop -> option and setting ->Datasource settings -> delete your existing sharepoint connection .

and try connecting to the sharepoint again 

Thanks 

Hi AhmedShalaby,

Thanks for reaching fabric communnity, will happy to assist.

Root Cause

• SharePoint.Files and SharePoint.Contents authenticate separately switching between them creates a new data source entry in Power BI
• Power BI looks for stored credentials for the new source, finds none, and throws the auth error even though you are already signed in
• This is not a permissions issue it's a cached credentials mismatch

Fix Clear & Re-authenticate

Step 1 Clear old credentials:

• File → Options and Settings → Data Source Settings
• Find all SharePoint entries → click "Clear Permissions" for each
• Click Close

Step 2 Re-authenticate:

• Go back to the SharePoint.Contents step in Power Query
• When the prompt appears → select Microsoft Account (not Anonymous or Windows)
• Click Sign In → complete login → click Connect

Step 3 Check your URL format:

• Use root site URL: https://yourorg.sharepoint.com/sites/YourSite 
  Not a subfolder: https://yourorg.sharepoint.com/sites/YourSite/Documents/Folder 
• SharePoint.Contents equires the root site URL only

Simpler Alternative Stay with SharePoint.Files

• SharePoint.Files is more reliable and easier to work with for most use cases
• Just point it at your root site and filter down in Power Query steps:

= SharePoint.Files("https://yourorg.sharepoint.com/sites/YourSite", [ApiVersion = 15])​

If Error Still Persists

• Ensure Microsoft Account is selected not Windows or Anonymous
• Complete any MFA prompt fully before clicking Connect
• Confirm your account has at least Read access on the SharePoint site
• Try opening Power BI in a different browser if the OAuth popup gets blocked

Hope this resolves it! Mark as Accepted Solution if it helped