Fabric SQL database is stopped working while calling from WebApi

[saimanjiri]

Hello, 

We are calling Fabric SQL db from webapi through Managed Identity. It was working till yesterday without issue, suddenly started throwing below error from yesterday afternoon. We havent made any changes, what could be the reason? Please assist

[v-sgandrathi]

Hi @saimanjiri,

Thank you for reaching out.
The error indicates that the managed identity your Web API uses may no longer have the necessary permissions to access the Fabric SQL database. This can happen due to expired tokens, permission changes, or updates in Azure AD or resource settings, even if you didn't make any changes.

Please check if the managed identity still exists as a database user by running: SELECT * FROM sys.database_principals WHERE name = '<YourManagedIdentityName>'. If it's missing, recreate it with: CREATE USER [<ManagedIdentityName>] FROM EXTERNAL PROVIDER; and assign roles like db_datareader and db_datawriter. Also, make sure your Web API is still set to use Managed Identity in the connection string. If the problem continues, please provide the identity name and error timestamp for further investigation.

Thank you and continue using Microsoft Fabric Community Forum.

[v-sgandrathi]

Hi @saimanjiri,

We wanted to follow up since we haven't heard back from you regarding our last response. We hope your issue has been resolved.

Thank you.

[v-sgandrathi]

Hi @saimanjiri,

Just checking in -- have you had a chance to review and try the provided solution? Kindly share the status whenever you get a chance.

Looking forward to your response.

[saimanjiri]

Hello, 

We are calling Fabric SQL db from webapi through Managed Identity. It was working till yesterday without issue, suddenly started throwing below error from yesterday afternoon. We havent made any changes, what could be the reason? Please assist