Excel connection to azure mysql database error 'SSPI call failed'

Question

Suddenly last week the dataconnection to the database on azure failed with error '...SSPI call failed...'.

Excel connects with the .NET connector.

All PC's have the same problem.

Connections from other applications (no excel) work fine.

All research point to SSL-connection problem, but certificates did not change and the non-excel applications have no problem.

If anyone had the same problem and/or a suggestion: help is appreciated.

Thank you

Answer 1

Dear @Ivo Hubert, 

Good day! Welcome to Microsoft Q&A forum! 

Based on your description, I understand that you’re experiencing an issue where Excel is no longer able to connect to an Azure MySQL database using the .NET connector, and the connection now fails with an “SSPI call failed” error. This problem started suddenly last week and affects all PCs, even though other non‑Excel applications can still connect successfully. Your investigation suggests an SSL-related issue, but the certificates have not changed and the problem appears to be isolated to Excel, so you’re looking for guidance or confirmation from others who may have encountered the same situation.

I sincerely apologize for the inconvenience caused by this issue.

Regarding this situation, because the issue affects multiple machines and started recently without any changes to certificates or infrastructure, it’s likely related to how Excel is handling authentication or SSL internally.

For that reason, I recommend raising a Microsoft Support ticket so the Excel product team can investigate directly. This approach avoids unnecessary trial-and-error and gives us the fastest path to a reliable, long-term fix, especially since Excel connectivity is critical for reporting and daily operations.

To resolve this, Microsoft’s support team will need to step in. A Technical Support Engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.    

As forum moderators, we don’t have access to the detailed logs or backend systems needed to troubleshoot this effectively due to privacy and security constraints. For that reason, the most efficient solution would be to contact Microsoft’s support team directly.    

Here’s what your IT Global Admin should do next:  

Submit a Service Request: The Global Admin should create a service request with Microsoft support to get advanced technical assistance and diagnostics. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin. 

When submitting the ticket, it will be helpful to include:

• The exact error message: SSPI call failed
• Excel version and update channel
• Azure MySQL version and authentication method
• Confirmation that non-Excel applications connect successfully
• Approximate timeframe when the issue first appeared (last week)
• Confirmation that no SSL or certificate changes were made

Kindly let me know when there are updates or if you need further assistance. Any updates you’re able to share would be really helpful. I appreciate your time and look forward to hearing how things are going! 

Thank you for your time and patience.

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Answer 2

The error message "SSPI call failed" typically indicates an issue with the authentication process when connecting to a database. Since you mentioned that connections from other applications work fine, it suggests that the problem may be specific to Excel or the .NET connector being used.

Here are some steps you can take to troubleshoot the issue:

1. Check the Connection String: Ensure that the connection string used in Excel is correct and matches the one used in other applications that are working.
2. Update the .NET Connector: Make sure that you are using the latest version of the .NET connector for MySQL. An outdated connector may cause compatibility issues.
3. Firewall and Network Settings: Verify that there are no firewall or network settings that could be blocking Excel's connection to the Azure MySQL database.
4. SSL Configuration: Since you suspect an SSL connection issue, ensure that the SSL certificates are correctly configured in Excel. You may need to download and install the appropriate certificates if they have changed or if there are updates.
5. Check for Updates: Ensure that Excel and the operating system are fully updated, as updates can sometimes resolve connectivity issues.
6. Test with Different Credentials: If possible, test the connection using different credentials to rule out any account-specific issues.

If these steps do not resolve the issue, you may want to consult the Azure documentation or support for further assistance regarding SSL configurations and connection settings specific to Azure Database for MySQL.

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References:

• Troubleshoot connection issues to Azure Database for MySQL - Flexible Server