Error while refreshing dataflow gen2

[Shubham_rai955]

Facing this issue while refreshing the dataflow, Implemented incremental refresh, and not doing any transformaition using M query in any table. Please guide me how to resolve this.

[AntoineW · Accepted solution]

Hello @Shubham_rai955,

✅ Why this happens

Even though you mentioned no transformations in M, the incremental refresh policy still applies filters and type conversions. If any column expected as Number contains a Text value (or vice versa), Power Query throws this error.

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✅ How to fix it

1. Check column data types in the source

   • Ensure that the column used for incremental refresh (usually a date or numeric key) and any numeric columns are consistently typed.
   • If the source has mixed types (e.g., numbers stored as text), clean them before refresh.

2. Add explicit type conversion in Power Query

   • In the Dataflow Gen2 editor, select the problematic column → set Data Type to Text or Number explicitly.
   • Or use try ... otherwise in M to handle invalid values

3. Validate incremental refresh filters

   • If the policy applies on a column that isn’t strictly numeric or date, adjust it.

4. Preview the query in the editor

   • Check for rows with unexpected values (e.g., text in numeric columns).

You can also Re-run a full refresh once

• Disable incremental refresh temporarily.

• Run a full refresh to confirm if the issue is only with incremental partitions.

• If full refresh succeeds, re-enable incremental refresh.

Hope it can help you ! 

Best regards,

Antoine