Problem/bug with @azure/ai-agents with GPT-5.2

Question

Hello,

I am encountering a reproducible issue with GPT-5.2 when using Azure Agents (@azure/ai-agents).

• Scenario

1. I create a conversation using @azure/ai-agents
2. I upload a PNG file as a message attachment and ask GPT-5.2 to analyze it → GPT-5.2 responds correctly
3. I then upload an XLSX file as message attachment and ask GPT-5.2 to analyze it → GPT-5.2 reports that it cannot see the file and cannot perform the analysis

• Additional tests : I reproduced the same behavior in the official Azure AI Foundry Playground(as message attachment and thread attachment)
• The issue occurs even when : the file is attached to the user message or thread, the file ID is explicitly provided in the run toolResources.codeInterpreter.fileIds, No error is returned, but the model claims it cannot access the file.
• Expected behavior: GPT-5.2 should be able to access and analyze newly attached files within the same conversation, as it does on the first response.
• Actual behavior: GPT-5.2 cannot access the file after the first response and reports that it cannot see the file.
• Comparison GPT-4.1 works correctly with the same code and same steps The issue appears to be specific to GPT-5.2

Has anyone encountered this issue, or is this a known limitation or bug with GPT-5.2 in Azure Agents?

Thank you.

Answer 1

This is a Chat Playground UI limitation, not a problem with the XLSX file or the GPT-5.2 model itself.

Root Cause

• GPT-5.2 + Code Interpreter does support non-image files (XLSX, CSV, etc.)
• But that support is only available in Agents / Assistants / API flows, where files are passed via tool_resources.code_interpreter.file_ids
• The Chat Playground UI does not currently expose non-image uploads, even though the model advertises the capability
• This results in a mismatch between the Chat Playground UI and the model’s supported capabilities..

The attached screenshot shows:

• The model states that .xlsx uploads are supported
• The Playground UI is rejecting the same .xlsx file as “image-only”

This confirms the issue occurs before the request reaches the model.

Recommended workaround

• Use Azure AI Foundry → Agents (or SDK/API) with Code Interpreter enabled to upload and analyze .xlsx files
• Ensure files are attached before creating a new run
• If staying in Playground, convert the file to CSV and paste the content manually (limited, but it works)

Summary

This behavior is reproducible and appears to be a limitation of the Chat Playground UI, not a bug in GPT-5.2 or the XLSX file itself.

Clarifying the supported file types per deployment in the Chat Playground UI would help avoid this confusion.