Unknown evaluation error code: 104100 With DataFlow Gen2

[mklevemann]

I've been getting this error with DataFlow Gen2 and have narrowed it down to a pivot step I am doing.   I have a super simple table with 3 fields, Key, Name, and date;  I'm pivoting on name.   Any ideas how to troubleshoot?

[mklevemann · Accepted solution]

So after a bunch of trial and error, I finally found the issue;  after the pivot I had some rows in [error] and once I removed them it loaded successfully.   

[v-veshwara-msft]

Hi @mklevemann ,

Thanks for reaching out to Microsoft Fabric Community.

The error code 104100 in Dataflow Gen2 usually comes up as a generic evaluation error. This can happen in situations where staging is enabled on intermediate queries or when the query structure introduces conflicts. Disabling staging on the related queries or simplifying the transformation has helped resolve this in some situations, as discussed here:

Solved: Re: Dataflow Gen2 (CI/CD) Non-deterministic failur... - Microsoft Fabric Community

Solved: DataFlow Gen2 104100 Couldn't refresh the entity b... - Microsoft Fabric Community

Since you’ve narrowed it down to the pivot step, the error could be related to duplicate or inconsistent Name values that generate duplicate column names after pivoting, or multiple Key–Date values under the same Name which require an aggregation. A mismatch in the data type of the column being aggregated can also lead to this issue.

If the error persists after verifying the above points, I recommend raising a support ticket to have this investigated further.

Here is the guide on how to raise a support ticket: How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

Hope this helps. Please reach out for further assistance.

Thank you.