Medium severityprivacy
Power BI Refresh Error:
Formula.Firewall
What does this error mean?
Power Query's privacy firewall blocked a query because it would combine data from sources with different privacy levels. This is a security mechanism that prevents accidental data leakage between sources.
Common causes
- 1A query reads from a database and an API (or any two sources) with mismatched privacy levels
- 2Parameters or values from one data source are being passed to a query against another source
- 3Privacy levels are set to 'None' (not configured) on one or more data sources
- 4A function that buffers data (List.Buffer, Table.Buffer) is reading across sources of different trust levels
How to fix it
- 1In Power BI Desktop: File → Options → Current File → Privacy → select 'Ignore the Privacy Levels and potentially improve performance'
- 2Alternatively, set consistent privacy levels on all data sources: File → Options → Global → Privacy
- 3In Power BI Service, go to dataset settings → Data source credentials → set the privacy level for each source to 'Organizational' or 'Public' as appropriate
- 4Restructure your M queries to avoid passing values from one source into queries against another source
- 5Use a SQL view or stored procedure to pre-join data on the server side, eliminating cross-source combinations in Power Query