Getting an error while creating a SharePoint onpremise connection under the on-premises data gateway

[Bhaskar_D]

Hi All, 
Getting an error while creating a SharePoint on-premise connection under the on-premises data gateway

Error details: 

Unable to update connection credentials. Unable to connect to the data source. Either the data source is inaccessible, a connection timeout occurred, or the data source credentials are invalid. Please verify the data source configuration and contact a data source administrator to troubleshoot this issue.

 Gateway: Timeout expired. The timeout period elapsed prior to completion of the operation. 
Status code: 400 

Checked both the network and SharePoint side, but couldn't find any clues as to what might be causing the issue.

Any suggestions would be greatly appreciated.

Thank you

[Bhaskar_D]

Hi @v-tsaipranay,

After rebooting all the SharePoint servers, the issue has been resolved. 

[v-tsaipranay]

Hi @Bhaskar_D ,

We haven’t received an update from you in some time. Could you please let us know if the issue has been resolved?
If you still require support, please let us know, we are happy to assist you.

Thank you.

[v-tsaipranay]

Hi @Bhaskar_D ,

Thank you for reaching out to the Microsoft Fabric Community Forum.

Could you please let us know if the issue has been resolved? I wanted to check if you had the opportunity to review the information provided by @Zanqueta and @cengizhanarslan . If you still require support, please let us know, we are happy to assist you.

Thank you.

[cengizhanarslan]

Most of the time this error happens because the gateway connection was created using a library/file URL instead of the SharePoint site URL.

Power BI / Gateway expects the root site as the data source, then you navigate to the list/library inside Power Query.

Use:

https://sharepoint.contoso.com/sites/Finance
(or on-prem: https://sharepoint.contoso.local/sites/Finance)

Not:

https://.../Shared Documents/...
https://.../Forms/AllItems.aspx
direct file links to .xlsx/.csv

[Zanqueta · Accepted solution]

Hi @Bhaskar_D.

It is usually related to three main factors: credentials, gateway configuration, or data source accessibility.

---

1. Verify the Authentication Type

• For SharePoint On-Premises, the gateway supports Windows Authentication (Kerberos/NTLM).
• Ensure that:
  • You are using domain credentials (e.g., DOMAIN\username).
  • The account has read permissions on the SharePoint library or list.
  • If using HTTPS, confirm that the certificate is trusted.

---

2. Test Connectivity from the Gateway Server

• On the server where the On-Premises Data Gateway is installed:
  • Open a browser and attempt to access the SharePoint site using the same credentials.
  • If additional authentication is required (e.g., NTLM combined with MFA), this may cause the failure.
• You can also run:

Test-NetConnection <SHAREPOINT_URL> -Port 443

to confirm that there are no network blocks.

---

3. Adjust Timeout

• The error mentions a timeout, which can occur if the list or library is very large.
• In Power BI Service, you cannot directly increase the timeout, but you can:
  • Reduce the data volume (apply filters in Power Query).
  • Ensure the Gateway is updated to the latest version.

---

4. Check Gateway Configuration

• In Power BI Service:
  • Navigate to Settings > Gateways > Connections.
  • Confirm that the Gateway is online and that the connection is assigned to the dataset.
• If using Kerberos Constrained Delegation, verify that it is correctly configured in Active Directory.

---

Official Documentation for Reference

• SharePoint - Connectors | Microsoft Learn
• On-premises data gateway - Power BI | Microsoft Learn

---

Practical Suggestion:
Start by testing with a dedicated service account (without MFA) and confirm that the Gateway can authenticate directly to SharePoint. If this works, the issue is likely related to credentials or advanced authentication.

If this response was helpful in any way, I’d gladly accept a 👍much like the joy of seeing a DAX measure work first time without needing another FILTER.

Please mark it as the correct solution. It helps other community members find their way faster (and saves them from another endless loop 🌀.