Forum Discussion
DataSource.Error - Value Cannot be Null
Thank you for the reply! It ended up being on the Historian end where the parameter wasn't getting returned. There's a query limit that needs to be adjusted, so once I upped that value, data started coming through.
Hi EBradley,
Thank you for reaching out to the Microsoft fabric community forum. After reviewing the details you provided, I have identified few workarounds that may help resolve the issue. Please follow these steps:
The error "Value cannot be null. Parameter name: pUnk" in Power BI when using OLE DB as a data source usually indicates an issue with the OLE DB provider or the connection setup.
Please ensure that the GE Historian OLE DB provider (if using GE iHistorian) is correctly installed. Reinstall or update the OLE DB provider to match your system architecture (32-bit vs. 64-bit). Verify that your connection string includes the required parameters, such as Data Source, Initial Catalog, User ID, and Password. Consider using the Microsoft OLE DB Driver for SQL Server instead of the Historian-specific provider.
Test the connection in Excel or another tool to verify access. Ensure that the account has read permissions for the Historian database. Try using ODBC instead of OLE DB, or, if possible, retrieve the data through an SQL Server connection. Refresh the dataset and check for errors in Power Query steps. Simplify the query and manually add parameters if necessary.
If the issue persists, please provide your connection string and error details for further troubleshooting.
Refer to the below following link for better understanding:
OLE DB Power Query Data Connector - Power Query | Microsoft Learn
I hope this could resolve your issue, if you need any further assistance, feel free to reach out.
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