Error Loading Data from Dataflow Gen2 to Microsoft Fabric Data Warehouse

[lucasgalde]

I am experiencing an issue with all my Dataflows Gen2 in Microsoft Fabric. The process loads the data successfully but fails to transfer it to the Fabric Data Warehouse. The error message received is:

"Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Expression.Error: Table is not a Lakehouse SQL table Details: Reason = Expression.Error;Detail = Lakehouse.SqlTable;Microsoft.Data.Mashup.Error.Context = System".

This issue started today for all my Dataflows Gen2, which were previously working fine. There have been no changes to the pipeline configuration or the Data Warehouse. The error suggests that the table is not a "Lakehouse SQL table," but my destination has always been a Data Warehouse, not a Lakehouse.

Is anyone else experiencing this issue? Could this be related to a recent update?

Any insights or solutions would be greatly appreciated. Let me know if you need additional details.

[v-nmadadi-msft]

Hi @lucasgalde,

As we haven’t heard back from you, we wanted to kindly follow up to check if the solution provided by the community members for the issue worked. If our response addressed, please mark it as Accept as solution and click Yes if you found it helpful.

Thanks and regards

[v-nmadadi-msft]

Hi @lucasgalde 

I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions. If our responses has addressed your query, please accept it as a solution and give a 'Kudos' so other members can easily find it.

Thank you

[v-nmadadi-msft]

Hi @lucasgalde,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[v-nmadadi-msft]

Hi @lucasgalde,
Thanks for reaching out to the Microsoft fabric community forum.

To Add to the valuable points mentioned by @nilendraFabric, Disabling the staging feature in Power Query appears to have resolved the issue. Users have reported that, after making this change, the loading speed improved significantly—averaging less than five minutes—while occurrences of the error became rare.

If you find this post helpful, please mark it as an "Accept as Solution" and consider giving a KUDOS.
Thanks and Regards

[lucasgalde]

Hi @v-nmadadi-msft,

Thank you for your response!

In my case, my Gen2 is connected to a Fabric Data Warehouse, where enabling the staging option is mandatory. Because of this, I am unable to disable it to test this solution. 

Best regards

[v-nmadadi-msft · Accepted solution]

Hi @lucasgalde ,

Please chcek if these two scenarios are inadvertently causing the error:

The error message suggests a data type mismatch between your pre and post refresh data. For example, a column that previously contained datetime values is now containing only date values which may inadvertently cause the error.

Another possible reason for the issue, as you mentioned not encountering the error in Azure SQL Database and Lakehouse, could be that the data includes a datatype that is unsupported by Fabric Warehouse.
Document to check what data types are not supported by Warehouse:
Data types - Microsoft Fabric | Microsoft Learn


If you find this post helpful, please mark it as an "Accept as Solution" and consider giving a KUDOS.
Thanks and Regards

[nilendraFabric]

Hello @lucasgalde 

Dataflow Gen2 automatically uses a hidden staging Lakehouse, even when the final destination is a Data Warehouse. If this Lakehouse’s SQL analytics endpoint is misconfigured, errors occur during data transfer

try these

Delete the existing Lakehouse (or Data Warehouse) and republish the Dataflow Gen2 to force regeneration of metadata

try Disabling staging in Dataflow Gen2 settings

I have discussed this is details here

https://community.fabric.microsoft.com/t5/Service/Dataflow-Gen2-Not-loading-and-refreshing-data/m-p/...

[lucasgalde]

Hi @nilendraFabric ,

Thank you for your response!

In my case, my Gen2 is connected to a Fabric Data Warehouse, where enabling the staging option is mandatory. Because of this, I am unable to disable it to test this solution.

I explored a few alternatives:

• Changing the data destination to Azure SQL Database instead of the Warehouse, but this significantly increased the loading time.
• Creating a Lakehouse and loading the data there.
• Creating a new Warehouse from scratch and recreating the Gen2 Dataflow, but I still encountered the same error.

Best regards,