Base Model 20250808 Internal Error when training with Structure Text file
When I train a custom model using a structure text file and output file using 20250808 build (english) I get an failure for the model and it says internal error. The structure text and output files are error free when I uploaded them. I was successfully able to train a custom model using the same structure text and output files except with a older base model (20221013).
The docs don't say anything about newer models not accepting the structure text file. So I am seeking clarification on this matter. Thank you in advance.
-
Anshika Varshney 13,405 Reputation points • Microsoft External Staff • Moderator
Hi @Kaiyip Ho
This looks like a model/version-specific issue rather than a problem with your data.
Since the same structured text works with an older base model (20221013) but fails with 20250808, it likely indicates a limitation or backend issue with the newer model build. Similar “internal error / 500” behaviors are typically related to service-side issues or unsupported scenarios rather than file validation problems. [community.openai.com]
You can try the following:
Use the older base model temporarily (as you already confirmed it works)
Retry the training job after some time to rule out transient backend issues
Keep checking if there is any update on supported formats for the newer model
At the moment, it doesn’t look like an issue with your structured text file itself.
Hope this helps!
Thankyou!
-
Anshika Varshney 13,405 Reputation points • Microsoft External Staff • Moderator
-
Kaiyip Ho 0 Reputation points
Hello @Anshika Varshney
Thank you for the response. I have since tried training new base models with structure text files that don't have errors but same internal error on my end. I was just wondering if I get some confirmation from Azure if its actually a limitation or a bug that is being worked on. Either way I don't think its worth continuing spending time on this method.
-
Anshika Varshney 13,405 Reputation points • Microsoft External Staff • Moderator
Hello @Kaiyip Ho
Thank you for the update and for testing with additional structured text files.
Based on your findings, the issue does not appear to be tied to a specific training file, since multiple valid structured text files are resulting in the same Internal Error when used with the 20250808 base model, while the older 20221013 base model trains successfully with the same data. [learn.microsoft.com]
At this point, I can't definitively confirm from the public documentation whether this is an intended limitation of the 20250808 base model or a product issue. However, the behavior you've described strongly suggests that the problem is not caused by the structure text files themselves, especially given the successful results with the older base model.
Your feedback is valuable, and I agree that it may not be productive to continue investing time in this approach until there is clarification from the product team regarding support for structured text training with the newer base model.
If I receive any further information or confirmation regarding whether this is a known limitation or a bug, I'll update this thread.
Thank you for sharing your testing results. They provide useful information for others who may encounter the same behavior.
Sign in to comment