High severitygateway
Power BI Refresh Error:
MashupException.Error
What does this error mean?
The Power Query Mashup engine failed. In Dataflow Gen2, usually caused by port 1433 being blocked to the Fabric staging Lakehouse TDS endpoint.
Common causes
- 1The on-premises data gateway cannot reach the Dataflow Gen2 staging Lakehouse on port 1433 (TDS protocol)
- 2Firewall rules on the gateway server or proxy servers block outbound traffic to Fabric staging Lakehouse endpoints on port 1433
- 3Multiple queries in the dataflow reference each other — the dataflow engine must read staged data via TDS (port 1433) before writing the next query
- 4Note: dataflow writing to a Lakehouse uses HTTPS (port 443), but reading staged data between queries requires TCP port 1433
How to fix it
- 1Check the error detail for the failed activity 'WriteToDatabaseTableFrom_...' — confirm it is a TCP/port 1433 connectivity issue
- 2Update firewall rules on the gateway server to allow outbound TCP port 1433 to these endpoints: *.datawarehouse.pbidedicated.windows.net, *.datawarehouse.fabric.microsoft.com, *.dfs.fabric.microsoft.com
- 3To scope to a specific workspace, navigate to Fabric workspace → DataflowsStagingLakehouse → View Details and copy the SQL connection string
- 4Workaround (if firewall cannot be changed): combine referencing queries into a single query
- 5Workaround: disable staging on all referenced queries in the dataflow