ISSUE: Fabric SQL database replication error to one-lake

Hi Max_agileDSS 

The error you are seeing with SQL Database mirroring to OneLake is not caused by your setup alone but rather by how Microsoft Fabric now enforces security around mirrored databases. The message “The server principal is not able to access the database under the current security context” usually means the identity that Fabric uses to replicate data—specifically the System Assigned Managed Identity (SAMI) of the Azure SQL server—does not have the right access. Since you mention this was working fine last week and now fails in multiple tenants, it is likely due to a recent change in Fabric or Azure SQL permissions. To fix it, you should verify that the SQL logical server’s SAMI is enabled, that it is the primary identity (and not overridden by a User Assigned Managed Identity), and that it has Read and Write permissions on the mirrored database artifact in Fabric. You should also confirm that your workspace or tenant allows OneLake external access, and that the SAMI has been granted access to the source SQL database itself. In short, the feature itself hasn’t disappeared, but security enforcement appears to have tightened, so ensuring the SAMI has correct rights and configuration should resolve the replication error.