What causes DataFormat.Error?

You are connecting to a standard dataflow (one that stores data in Dataverse) using 'Get Data from dataflow' — only analytical dataflows support this connector. The error message may read: 'DataFormat.Error: We reached the end of the buffer'

How do I fix DataFormat.Error?

Check the type of dataflow you are connecting to — standard dataflows (Dataverse) cannot be accessed via 'Get Data from dataflow'.. If your dataflow stores data in Dataverse, use 'Get Data from Dataverse' instead.. Alternatively, recreate the dataflow as an analytical dataflow, which supports the 'Get Data from dataflow' connector.. Ensure the dataflow has been refreshed at least once before connecting — tables are empty until the first refresh runs.

Medium severityquery

Power BI Refresh Error:
DataFormat.Error

What does this error mean?

Power Query received data in an unexpected format. Common cause: connecting to a standard dataflow instead of an analytical dataflow ('end of buffer' error).

Common causes

1You are connecting to a standard dataflow (one that stores data in Dataverse) using 'Get Data from dataflow' — only analytical dataflows support this connector
2The error message may read: 'DataFormat.Error: We reached the end of the buffer'

How to fix it

1Check the type of dataflow you are connecting to — standard dataflows (Dataverse) cannot be accessed via 'Get Data from dataflow'.
2If your dataflow stores data in Dataverse, use 'Get Data from Dataverse' instead.
3Alternatively, recreate the dataflow as an analytical dataflow, which supports the 'Get Data from dataflow' connector.
4Ensure the dataflow has been refreshed at least once before connecting — tables are empty until the first refresh runs.

Frequently asked questions

Does this error only affect the dataset or also the report?

The error occurs during the refresh — if the refresh fails, the report shows the last successfully loaded data, not an error. Users won't see a broken report, but the data will be stale.

How do I find which Power Query step is causing the error?

Open Power BI Desktop and attempt a refresh. Power Query highlights the failing step in the Query Editor. The error message typically includes the table name and step name.

Can query errors be caused by data changes in the source?

Yes — if the source returns a data type the query doesn't expect (e.g., a null value in a previously non-nullable column), the query evaluation fails.

Does this error affect all tables in the dataset?

Usually only the table whose query evaluation failed. Other queries in the dataset may succeed unless they depend on the failed query's output.

Source · learn.microsoft.com/en-us/power-query/dataflows/troubleshooting-dataflow-issue-get-data-from-dataflow