What causes RfcBaseException?

An old version of the SAP .NET Connector (SAP NCo) is installed — the RfcBaseException.get_ErrorCode() method is missing in older versions. Multiple versions of the SAP .NET connector are installed simultaneously (version conflict). The SAP .NET connector was installed twice — once in the Global Assembly Cache (GAC) and once not in the GAC. Note: this error hides the real underlying SAP BW error; fixing the connector version reveals the actual problem

How do I fix RfcBaseException?

Perform a clean installation of the SAP .NET Connector — do not just upgrade over the existing installation.. Step 1: Uninstall the existing SAP .NET Connector.. Step 2: Verify the connector is gone from the GAC — confirm these paths do NOT contain DLLs: C:\Windows\Microsoft.NET\assembly\GAC_64\sapnco\ and C:\Windows\Microsoft.NET\assembly\GAC_32\sapnco\.. Step 3: Confirm no binaries remain in C:\Program Files\SAP\SAP_DotNetConnector3_Net40_x64 or C:\Program Files (x86)\sap\.. Step 4: Reinstall the connector (recommended: version 3.0.23) and make sure to check 'Install assemblies to GAC' during setup.

High severitydata source

Power BI Refresh Error:
RfcBaseException

What does this error mean?

The SAP .NET Connector threw an RfcBaseException, masking the real SAP BW error. Caused by version conflicts — fix requires a clean GAC reinstall.

Common causes

1An old version of the SAP .NET Connector (SAP NCo) is installed — the RfcBaseException.get_ErrorCode() method is missing in older versions
2Multiple versions of the SAP .NET connector are installed simultaneously (version conflict)
3The SAP .NET connector was installed twice — once in the Global Assembly Cache (GAC) and once not in the GAC
4Note: this error hides the real underlying SAP BW error; fixing the connector version reveals the actual problem

How to fix it

1Perform a clean installation of the SAP .NET Connector — do not just upgrade over the existing installation.
2Step 1: Uninstall the existing SAP .NET Connector.
3Step 2: Verify the connector is gone from the GAC — confirm these paths do NOT contain DLLs: C:\Windows\Microsoft.NET\assembly\GAC_64\sapnco\ and C:\Windows\Microsoft.NET\assembly\GAC_32\sapnco\.
4Step 3: Confirm no binaries remain in C:\Program Files\SAP\SAP_DotNetConnector3_Net40_x64 or C:\Program Files (x86)\sap\.
5Step 4: Reinstall the connector (recommended: version 3.0.23) and make sure to check 'Install assemblies to GAC' during setup.

Beyond the docs

Common practitioner solutions not covered in the official documentation.

1After reinstalling, restart the Power BI Desktop or gateway service to load the new connector

Frequently asked questions

Does this error affect multiple datasets at once?

If multiple datasets connect to the same data source, yes — all of them will fail until the source connectivity is restored.

Can this error be caused by a server migration or rename?

Yes — if the server name, database name, or connection string changed (e.g., during a cloud migration), Power BI still holds the old connection details. Update the connection in Power BI Desktop and republish.

Does this error appear in Power BI Desktop?

Sometimes — if you open the .pbix file and attempt a refresh, Desktop will surface the same connection error. This is useful for debugging without affecting the Service dataset.

Will the error resolve automatically once the source is back online?

Only if it was a temporary outage. The next scheduled refresh will succeed automatically. If the connection string changed or credentials expired, manual intervention is needed.

Source · learn.microsoft.com/en-us/power-query/connectors/sap-bw/sap-bw-troubleshooting