Copilot Studio agent accepts and analyzes unsupported file type (.bat) in Teams and Test panel, contrary to documented file input list

2026-10-08T18:27:42.7266667+00:00

Hi all,

I’m testing file input on a Copilot Studio agent and seeing behavior that doesn’t match the documentation.

Documentation reference: Allow file input from users. It lists the supported file types as DOCX, CSV, PDF, TXT, JPG, PNG, WebP, and non-animated GIF. XLSX and PPTX are noted as experimental only.

What I did:

  • Turned on File uploads under Settings > Generative AI > File processing capabilities.
  • Uploaded a file named Test.bat. It contains plain instructional text, not a real batch script.
  • Tested in both the Test your agent panel in Copilot Studio and the Microsoft Teams channel.

Expected behavior: Based on the docs, I expected the .bat file to be rejected, ignored, or not processed, since it isn’t a listed supported type.

Actual behavior: In both Teams and the test panel, the agent read the file and replied with a summary of its contents.
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  1. Carl-L 23,105 Reputation points Microsoft External Staff Moderator
    2026-10-09T07:07:47.41+00:00

    Hello Govindappa Gari Reddisekhar Reddy,

    Welcome to Microsoft Q&A forum.

    Before we proceed further, may I know if the same agent can read actual .bat file? What I think right now is, even though .bat file is not supported, copilot is still capable of reading the content if it is simple enough.

    I'm waiting for your reply.

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