Copilot Agent Won't Read Uploaded Files

Question

Copilot Agent Won't Read Uploaded Files

Redalen, Ryan 5

A Microsoft 365 Copilot agent recognizes directly uploaded PDF and DOCX attachments by filename but intermittently does not receive their readable text. The issue reproduces in a new conversation started directly in the agent, including with one machine-readable PDF. The same PDF can be extracted successfully by other Copilot experiences. DOCX files also fail intermittently. Please investigate attachment content extraction and grounding for the agent runtime.

Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-08-12T07:56:06.9633333+00:00
To help narrow down the issue, could you please try the following:

Test with a newly created machine-readable PDF and a simple DOCX containing only a few lines of text.

Start a brand-new conversation directly with the agent and upload only a single file.

Verify whether the issue occurs consistently with the same file or only intermittently.

Confirm whether the same file can be successfully processed in Microsoft 365 Copilot Chat or other Copilot experiences.

Share the agent type, publishing channel, conversation ID, timestamp of a failed occurrence, and screenshots of the interaction.

Since the files are recognized by filename but the extracted content is not consistently available to the agent, this may indicate an issue in the attachment content extraction or grounding pipeline. The above details will help determine whether the problem is file-specific, agent-specific, or a platform-side issue.
Redalen, Ryan 5 Reputation points

2026-08-12T17:56:57.64+00:00

Testing completed as requested. Still having the same issue. Files only work inconsistently.

Agent type: M365

Publishing channel: M365

Conversation ID: Unable to provide, Copilot won't return it.

Timestamp: 10:25 AM Pacific, August 12, 2026

2 answers

Your answer

Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-08-12T07:56:06.9633333+00:00

To help narrow down the issue, could you please try the following:

Test with a newly created machine-readable PDF and a simple DOCX containing only a few lines of text.

Start a brand-new conversation directly with the agent and upload only a single file.

Verify whether the issue occurs consistently with the same file or only intermittently.

Confirm whether the same file can be successfully processed in Microsoft 365 Copilot Chat or other Copilot experiences.

Share the agent type, publishing channel, conversation ID, timestamp of a failed occurrence, and screenshots of the interaction.

Since the files are recognized by filename but the extracted content is not consistently available to the agent, this may indicate an issue in the attachment content extraction or grounding pipeline. The above details will help determine whether the problem is file-specific, agent-specific, or a platform-side issue.
Redalen, Ryan 5 Reputation points

2026-08-12T17:56:57.64+00:00

Testing completed as requested. Still having the same issue. Files only work inconsistently.

Agent type: M365

Publishing channel: M365

Conversation ID: Unable to provide, Copilot won't return it.

Timestamp: 10:25 AM Pacific, August 12, 2026

Answer 1

Adler, Mario 5

Hi @Redalen, Ryan ,

We are seeing the exact same behavior in our organization.

Uploaded files are recognized by the agent and the filenames are visible, but the document content is unavailable when you ask follow up questions. The files are expired. The issue is not limited to a single file type and appears to affect multiple users.

We are currently running:

App Version: 2.20261015.7.0

Based on your last update, it looked like you planned to open a support ticket through the Microsoft 365 Admin Center.

Was there any outcome from that ticket that you can share? Did Microsoft identify a root cause, acknowledge a service-side issue, or provide any mitigation steps?

Any additional information would be greatly appreciated, as we are currently investigating what appears to be the same issue in our tenant.

Thanks in advance.

Best Regards Mario

Redalen, Ryan 5 Reputation points

2026-10-19T20:34:50.83+00:00

I am not an admin for our tenant, so can't submit anything. I reached out internally but haven't gotten anywhere. I am hoping an update fixes it at some point. Seems like a basic requirement for an agent...
Adler, Mario 5 Reputation points

2026-10-20T05:28:29.5133333+00:00

Thanks for the update.

We opened a support ticket with Microsoft on Friday and are currently investigating what appears to be the same issue. Based on our observations, the problem affects multiple users and different file types, with document filenames being recognized but the attachment content intermittently unavailable to the agent.

At this stage, we do not yet have any findings or a confirmed root cause to share. We will provide an update here as soon as we receive additional information or identify any relevant insights from the investigation.

Thanks for confirming that you are seeing the same behavior in your environment.

Answer 2

Redalen, Ryan 5

Testing completed as requested. Still having the same issue. Files only work inconsistently.

Agent type: M365

Publishing channel: M365

Conversation ID: Unable to provide, Copilot won't return it.

Timestamp: 10:25 AM Pacific, August 12, 2026

User's image

Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-08-25T12:10:29.6933333+00:00

The fact that the M365 agent recognizes the attachment/filename but intermittently cannot access the extracted content suggests the issue may be occurring in the attachment content extraction or grounding pipeline for the M365 agent runtime. At this point, it would be useful to capture a few failed vs. successful attempts with the exact timestamps and any available request/correlation IDs for further investigation.

Also, could you please check whether other users within your organization are experiencing the same issue with the same agent, or whether the problem is limited to your user/account? If possible, testing with another user would help determine whether this is a user-specific issue or an organization/agent-level issue.

Given that the issue is intermittent and persists across different files, if multiple users are affected, this may warrant investigation as a service-side issue rather than further changes to the agent configuration.
Redalen, Ryan 5 Reputation points

2026-08-25T15:40:36.5866667+00:00

It's not specific to me. Others are reporting the same issue with the same agent and others. It just happened again (8/25/2026 8:38 AM Pacific).
Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-09-04T10:17:41.3266667+00:00
We tested the scenario from our end and are currently not able to reproduce the issue. File uploads are working as expected, and the agent is able to read and process the uploaded file content successfully.

Since the issue appears to be intermittent, could you please try the following additional troubleshooting steps:

Sign out of Microsoft 365/Copilot completely, sign back in, and retest the scenario.

Test the agent in an InPrivate/Incognito browser session to rule out browser cache, cookies, or extensions.

Try a different supported browser and compare the behavior.

If the issue persists after these checks, since it appears to be intermittent and may require backend/service-level investigation, we recommend raising a support request through Microsoft 365 Admin Center → Help & Support. This will allow the support team to investigate the tenant/service configuration and review any relevant backend telemetry.
Redalen, Ryan 5 Reputation points

2026-09-04T19:09:10.1866667+00:00
thanks for testing. Still dealing with inconsistencies. I tried what you suggested. I will raise a ticket through the admin center.

"Here's what happened:

I attempted to retrieve the RFP and resume contents using document references that were presented to me (turn4search29, turn4search30, turn4search31).

The resume references appear to have been indexed earlier in the conversation, so I was able to retrieve and cite content from those resumes.

The RFP reference that should have contained the PDF content was no longer available to me. When I tried to access it, the system returned "Expired" rather than the document contents.

An expired reference means the underlying document content was not exposed to my current context, even though you uploaded it and may have successfully used it in a previous test.

So the issue is most likely one of these:

The PDF content was not re-indexed into the current chat context, even though the file was attached.

The document reference expired between turns, while the resume references remained available.

The PDF ingestion failed on the system side, while the Word documents succeeded.

Importantly, I don't see evidence that:

the PDF is corrupted,

the PDF is unreadable,

or that there is anything wrong with the file itself.Here's what happened:

I attempted to retrieve the RFP and resume contents using document references that were presented to me (turn4search29, turn4search30, turn4search31).

The resume references appear to have been indexed earlier in the conversation, so I was able to retrieve and cite content from those resumes.

The RFP reference that should have contained the PDF content was no longer available to me. When I tried to access it, the system returned "Expired" rather than the document contents.

An expired reference means the underlying document content was not exposed to my current context, even though you uploaded it and may have successfully used it in a previous test.

So the issue is most likely one of these:

The PDF content was not re-indexed into the current chat context, even though the file was attached.

The document reference expired between turns, while the resume references remained available.

The PDF ingestion failed on the system side, while the Word documents succeeded.

Importantly, I don't see evidence that:

the PDF is corrupted,

the PDF is unreadable,

or that there is anything wrong with the file itself."