What causes DF-MSSQL-ErrorRowsFound?

A source column contains a value that cannot be cast to the target type (e.g., a string in a numeric column). The sink SQL table has a NOT NULL constraint on a column that received a null value from the data flow. A unique key or primary key violation occurred when writing to the target table. The data flow has no error row handling configured, so any row-level error causes the entire flow to abort

How do I fix DF-MSSQL-ErrorRowsFound?

In ADF Studio, open the failing data flow's Sink transformation and go to the 'Error row handling' tab.. Enable 'Skip incompatible rows' or 'Redirect incompatible rows to error file' to prevent a single bad row from aborting the entire flow.. If redirecting error rows, configure a linked service for the error output path (e.g., ADLS or Blob) to capture rejected rows for inspection.. Run a debug preview on the Source transformation and sort by the column mentioned in the error message to identify the problematic rows.. Fix the upstream data or add a Derived Column or Filter transformation to handle or exclude rows that would violate constraints.

Medium severitydata source

Power BI Refresh Error:
DF-MSSQL-ErrorRowsFound

What does this error mean?

The ADF Mapping Data Flow encountered rows from SQL Server or Azure SQL that triggered errors — type cast failures, constraint violations, or write failures. By default, ADF treats any error row as fatal and aborts the data flow.

Common causes

1A source column contains a value that cannot be cast to the target type (e.g., a string in a numeric column)
2The sink SQL table has a NOT NULL constraint on a column that received a null value from the data flow
3A unique key or primary key violation occurred when writing to the target table
4The data flow has no error row handling configured, so any row-level error causes the entire flow to abort

How to fix it

1In ADF Studio, open the failing data flow's Sink transformation and go to the 'Error row handling' tab.
2Enable 'Skip incompatible rows' or 'Redirect incompatible rows to error file' to prevent a single bad row from aborting the entire flow.
3If redirecting error rows, configure a linked service for the error output path (e.g., ADLS or Blob) to capture rejected rows for inspection.
4Run a debug preview on the Source transformation and sort by the column mentioned in the error message to identify the problematic rows.
5Fix the upstream data or add a Derived Column or Filter transformation to handle or exclude rows that would violate constraints.

Frequently asked questions

Does this error affect all pipeline runs or just the current one?

Depends on the root cause. A persistent misconfiguration fails every run; a transient issue may resolve on retry. Check the run history.

Can this error appear in Azure Data Factory and Microsoft Fabric pipelines?

Yes — the same connector errors appear in both ADF and Fabric Data Factory pipelines.

How do I see the full error detail for an ADF pipeline failure?

In ADF Monitor, click the failed run, then the failed activity. The detail pane shows the error code, message, and sub-error codes.

Will downstream Power BI datasets be affected when an ADF pipeline fails?

Yes — a dataset refreshing after the pipeline will use stale data or fail if the target table was cleared. The Power BI refresh may succeed while serving wrong data.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/data-flow-troubleshoot-guide