Forum Discussion
Dataflow Gen2 Error message: Unexpected error occurred while creating your data destination
I'm having issues with refreshing a dataflow gen2. It gives the Error code: 101238, of which I can't find any documentation. It seems to suggest that the datatypes are not correct. However, I've tried refreshing it with a simple table containing all text columns and I still get the same error message.
Is it possible the source (AFAS) has something to do with it? I can query the data in the dataflow just fine. It's really the writing to the lakehouse (I've also tried Warehouse as a destination) that doesn't work.
I've created another dataflow with SQL as a source and that has not had any issues.
8 Replies
Hi JK_CM ,
Just checking in were you able to raise a support ticket with Microsoft regarding the Gen2 write issue? If so, would be great to hear if they shared any updates or workaround.
Regards,
Akhil.Unfortunately not, since I don't have the (admin) rights to do in this environment
Hi JK_CM
by any chance the data source in your case is on prem and u are using data gateway
Error 101238 in Dataflow Gen2 typically occurs when writing data to a Lakehouse or Warehouse destination, often linked to connectivity issues, gateway configurations,
No, I'm using a REST API. When I use a dataflow Gen1, I'm not having any issues.
Hi JK_CM
Thanks for confirming it's a REST API. Since Gen1 works fine, the issue is likely with how Gen2 handles writing to the Lakehouse or Warehouse.
A few quick things to check.
- Make sure all column names are clean (no special characters or duplicates).
- Try manually setting data types instead of relying on auto-detection.
- Test writing to a brand new Lakehouse or Warehouse to rule out schema conflicts.
- Also try switching between append and replace as the load method.
Gen2 can be a bit sensitive with schema mapping, especially during write operations.
Let us know if any of these help.
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Best regards,
Akhil.I've tried this with a single table containing 9 rows and three text columns and am still getting the same error. I've switched to a notebook, which seems to work. It's very unfortunate, because I really like working with dataflows.
Hi JK_CM
Totally get that, when something so simple won’t go through. And yes, it’s odd that even a tiny table with all text fields fails. Good to hear notebooks are working as a workaround but agreed, it’s not as convenient as dataflows for quick transformations. This might be a backend bug with the Gen2 writer. Might be worth logging a support ticket with Microsoft, especially since Gen1 works fine and it’s clearly not a data issue. I’d recommend raising a support ticket with Microsoft so it’s officially logged and can help influence future improvements. You can do that here. https://learn.microsoft.com/en-us/power-bi/support/create-support-ticket
Regards,
Akhil.Hi JK_CM ,
Thanks for the update. Since you don’t have the necessary admin rights in your current environment, the best next step would be to reach out to your ADMIN. Our Internal support team will assist you on the issue.
Regards,
Akhil.
