Excel Power Query / Analysis Services authentication fails after reopening workbook

[BIscoverer]

Hi everyone,

I am experiencing an issue in Excel desktop when using Power Query to connect to an Analysis Services model with Microsoft Entra SSO. I am using SQL Server Analysis Services database connector (for Import), but the model is in Azure Analysis Services.

The first sign-in and refresh work fine. However, after I close and reopen the workbook, refresh often fails with “AnalysisServices: Authentication failed.”

What seems unexpected is that Excel does not show a sign-in prompt again. If the existing Entra session cannot be reused, I would expect the login window to appear instead of only returning an authentication error.

The only workaround I found so far is to clear/recreate the credentials in Data Source Settings, but that is only temporary.

Has anyone seen this issue with Excel + Power Query + Analysis Services using Entra SSO? Is it a known issue or related to a specific Excel build?

Thank you!

[v-menakakota]

Hi @BIscoverer ,
Thank you for reaching out to the Microsoft Community Forum.

This matches a token reuse issue where Excel holds onto an invalid Entra token and doesn’t trigger a fresh sign-in, which is why clearing credentials only works temporarily. Since the XMLA (Analysis Services) connection works reliably across sessions while the Power Query import path does not, this points to a connector-specific limitation or bug rather than expected SSO behavior. If token persistence were inherently unsupported, the XMLA connection would fail the same way but it doesn’t.

Given you’re on Monthly Enterprise Channel, this is likely tied to the Excel build and how the SSAS connector in Power Query handles modern auth/token refresh. In practice, the only stable workarounds today are using the XMLA path where possible or continuing with credential reset / full Office re-auth cycles.

At this point, it’s worth raising a Microsoft Support ticket so they can confirm if this is a known issue or build-specific limitation and advise on a fix or timeline: How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

 Best Regards, 
Community Support Team.

[BIscoverer]

Hi @v-menakakota, 

Thank you, this is the clearest diagnosis I have received so far and matches exactly what I'm seeing.

I have an update that further supports the build-specific theory: a colleague on the same Monthly Enterprise Channel but on Version 2602 (Build 19725.20170) has no issues with the same AAS model. Credentials persist and refresh works reliably after reopening the workbook. 

Since my organization manages updates centrally, I'm waiting for the 2602 update to come through and will confirm whether it resolves the issue.

Regarding the support ticket, thanks, I will consider raising one, especially if the 2602 update doesn't resolve it. It would be useful to get confirmation from Microsoft on whether this was a known regression and what specifically was fixed.

[v-menakakota]

Hi @BIscoverer ,

Could you please confirm if the issue has been resolved after raising a support case? If a solution has been found, it would be greatly appreciated if you could share your insights with the community. This would be helpful for other members who may encounter similar issues.

Thank you for your understanding and assistance.

Best Regards, 
Community Support Team.

[BIscoverer]

Hi @v-menakakota,

I have a significant update. I've since been updated to Version 2602 (Build 19725.20170), which is the same version my colleague is on. The issue persists for me, but not for him. To isolate further, we ran a test: my colleague logged into my laptop with his account and tried to refresh the same workbook (shared via OneDrive). He experienced the exact same failure: credentials work after manually re-entering them, but the token doesn't persist across sessions. On his own laptop, the same file refreshes without any issues.

This confirms the problem is machine-specific, not tied to user profile, Excel version, file, or AAS configuration.

Could you recommend additional steps on how to resolve this?

[v-menakakota]

Hi @BIscoverer ,

I think the Excel is reusing a stale Entra token from the Windows/Office auth layer (WAM) and not triggering a fresh sign-in, which is why it fails after reopen but works after clearing credentials.

Reset the local identity cache, not just Power Query credentials, sign out of Office, clear Credential Manager (Office/ADAL/Azure entries) and delete the Office identity cache folders (Identity / OneAuth). If it still fails, run an Online Repair or test with a new Windows profile. 

Best Regards, 
Community Support Team.

[BIscoverer]

Hi @v-menakakota ,

Thank you for the response.

I have already gone through most of these steps. I've cleared credentials in Data Source Settings, cleared relevant entries in Credential Manager, performed a full Office sign-out/sign-in cycle, and had Office completely reinstalled on this machine. None of these resolved the issue persistently: credentials work after manually re-entering them, but the token does not survive a close/reopen cycle.

[v-menakakota]

Hi @BIscoverer ,

From what you are telling me, I think this maybe Windows auth layer (WAM) or a machine-level policy/security component interfering with token persistence. At this stage, the only meaningful checks left are to disconnect/reconnect the Work or School account in Windows, test with a new Windows profile and compare any endpoint security or GPO differences with the working machine. If it still persists, I suggest the issue with Microsoft as device level SSO/WAM issue.

Best Regards, 
Community Support Team.

[v-menakakota]

Hi @BIscoverer ,

I hope the above details help you fix the issue. If you still have any questions or need more help, feel free to reach out. We’re always here to support you.

Best Regards, 
Community Support Team

[Olufemi7]

Hello @BIscoverer,

This is expected behavior with Excel + Power Query + Azure Analysis Services using Entra (Azure AD) SSO. Excel caches the token from the first refresh, but the token isn’t persisted across workbook sessions. When you reopen the workbook, the cached token is no longer valid, and Excel does not prompt for login, resulting in “Authentication failed.”

Workarounds:

1. Use the Azure Analysis Services connector instead of SQL Server Analysis Services for better SSO handling.

2. Make sure you are signed into Excel with your organizational account before refreshing.

3. Clear and re-enter credentials via Data Source Settings if a refresh fails (temporary fix).

4. Update to the latest Excel build, which has improved token handling.

5. For automated or frequent refreshes, use Power BI Service or Power Automate, which handle SSO tokens more reliably.

Microsoft documentation supporting this:

• Connector authentication behavior: Authentication in desktop apps

• Azure Analysis Services connector (Organizational account required): Azure Analysis Services database

[Zanqueta]

Hi  @BIscoverer

In practice, Excel sometimes attempts to re‑use an expired or invalid SSO token without triggering the interactive sign‑in flow. Because the SSAS connector relies on an authentication broker external to Excel, the workbook ends up in a state where:

• an invalid token persists in the credential cache;
• Excel does not display a login prompt;
• Power Query returns an authentication error instead of requesting fresh credentials.

  Please, try follow this steps:
  
  

  • Clearing credentials works temporarily because it forces a new interactive sign‑in.
  • Updating Excel to Current Channel, switching to the XMLA connector, ensuring modern auth is enabled, or performing a full Office sign‑out/sign‑in typically resolves the issue.

[BIscoverer]

Hi @Zanqueta,

Thank you for the suggestions.

Your description of the problem matches what I'm experiencing, the token isn't persisted across sessions and Excel doesn't prompt for re-authentication.

I am signed into Excel with my organizational account. I also tried a full Office sign-out/sign-in cycle (File >> Account >> Sign Out, closed all Office apps, reopened and signed back in). The issue returned the next day.

Clearing credentials in Data Source Settings works but is only temporary, as you noted, so this is not going to be a long-lasting solution.

I tested the traditional Analysis Services connection via Get Data >> From Database >> From Analysis Services (XMLA connector) and it works reliably across sessions. However, this only gives me a PivotTable/Power Pivot view. I need Power Query import mode so users can apply transformations, and that's the path where authentication fails.

My organization manages updates on Monthly Enterprise Channel, so I can't switch channels myself. I am currently on version 2512 (Build 19530.20226)