Copilot Notebook: OneDrive folder reference returns “file was not found”, while individual files work

Question

Copilot Notebook: OneDrive folder reference returns “file was not found”, while individual files work

Copilot Notebook User 0

I am experiencing a reproducible issue with OneDrive folder references in Copilot Notebooks.

The issue originally appeared in an existing project Notebook that had previously used OneDrive folder references. To isolate the problem, I created a completely new Test Notebook.

Controlled test:

In the Test Notebook, I open References → OneDrive.
OneDrive opens correctly and displays folders and files.
I select a test folder.
The folder is successfully added and appears under References → Folders.
When I ask Copilot to retrieve information using only that folder reference, it fails with:

“Can't provide more information as the file was not found.”

I then selected an individual Word document located inside the same folder, using the same Notebook and browser session.

The individual file works correctly. Copilot can retrieve the document and summarise its contents.

Test results:

OneDrive access: PASS
Browsing folders and files: PASS
Selecting a OneDrive folder: PASS
Adding the folder to References: PASS
Retrieving content through the folder reference: FAIL
Adding an individual file from the same folder: PASS
Retrieving content from that individual file: PASS

I also removed and re-added the folder reference through References → OneDrive, but the result was unchanged.

This appears to isolate the problem to folder-level reference retrieval/grounding, rather than general OneDrive connectivity, permissions or access to the underlying files.

The same type of folder-reference failure affected my original project Notebook, which had previously relied on OneDrive folder references.

Questions:

Is this a known issue with OneDrive folder references in Copilot Notebooks?
Has anyone reproduced a situation where an individual OneDrive file works but its containing folder fails as a reference?
Is there a workaround that preserves folder-level references rather than requiring every document to be added individually?
How can this issue be escalated to the appropriate Copilot Notebooks product/support team?

I can provide redacted screenshots showing the folder selection, the folder appearing in References, the retrieval error, and successful retrieval of an individual file from the same folder.

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1 answer

Your answer

Answer 1

Carl-L 24,580 Microsoft External Staff Moderator

Hello Copilot Notebook User,

Welcome to Microsoft Q&A forum.

As I checked, there are a few reports about the grounding reference issue. However, they seem to have been fixed. For now, a workaround that I can find is to remove the current reference and use Add references > link and use the OneDrive URL instead.

Before we proceed further, may I have a photo of the situation to check for you? Please remember to remove all personal information before posting.

I'm waiting for your reply.

Copilot Notebook User 0 Reputation points

2026-11-03T18:06:31.48+00:00
Hello,

Thank you for your reply and for suggesting that I remove the current Reference and add it again through Add references → Link, using its OneDrive URL.

As requested, I have attached screenshots of the situation. I also performed several controlled tests of the suggested workaround. The results show that the main problem is not simply the displayed 20-item warning. The main problem is that References are accepted and displayed in Copilot Notebooks, but they do not function consistently as grounding sources.

1. Main problem: References do not work reliably

Files and folders can be added to the References panel, but Copilot does not consistently:

retrieve files contained in a referenced OneDrive folder;

recognise specifically named files that are visibly present in that folder;

access a document added directly through its OneDrive URL;

ground answers in the referenced content;

or provide consistent results when the same Reference method is used with different OneDrive folders.

Microsoft’s documentation says that files and entire OneDrive folders can be added as References, and that Copilot can use supported files stored in an added location to answer questions, summarise information, or generate content. It also says that References should remain current as the underlying content changes:

Microsoft Support: Add references to a Microsoft Copilot Notebook

My controlled tests produced the following results.

Test A: Controlled two-document folder, successful

I created a new OneDrive folder containing two Word documents. Each document contained a different unique test code.

I added the folder through:

Add references → Link → OneDrive folder URL

Copilot successfully retrieved both codes from the two documents:

HWR-FOLDER-A-2026

HWR-FOLDER-B-2026

This showed that the folder-URL method can work.

Test B: Real project folder 00_CONTROL, successful

I added a small real project folder through its OneDrive URL. Copilot successfully:

identified the correct document in the folder;

retrieved the controlled reference hierarchy;

identified S-01 as the priority source for factual discrepancies concerning the finally approved strategy;

and correctly retrieved the rule that reference practices do not independently create mandatory requirements.

This showed that the method can also work with real project content.

Test C: Parent folder 00_EU_Normativna_ramka, failed

I added the parent folder through its OneDrive URL.

Copilot recognised the Reference but reported that the available retrieval did not expose its immediate children. It could not identify documents contained in either:

01_FUNDAMENTAL

02_KEY_PROVISIONS

Test D: Direct subfolder 01_FUNDAMENTAL, failed

I removed the parent-folder Reference and added 01_FUNDAMENTAL directly through its own OneDrive URL.

The signed-in OneDrive view clearly shows six supported Word documents inside that folder:

EU-01_01_FUNDAMENTAL.docx

EU-02_02_FUNDAMENTAL.docx

EU-03_03_FUNDAMENTAL.docx

EU-04_04_FUNDAMENTAL.docx

EU-05_05_FUNDAMENTAL.docx

EU-06_06_FUNDAMENTAL.docx

However, Copilot responded:

“I cannot verify any accessible documents in the direct 01_FUNDAMENTAL folder Reference. The retrieval returned no matching files, so I won’t guess.”

I then asked Copilot to access two specifically named files, EU-01_01_FUNDAMENTAL.docx and EU-06_06_FUNDAMENTAL.docx. Neither file was returned by retrieval.

Test E: Direct document URL, failed

I added EU-01_01_FUNDAMENTAL.docx directly using:

Add references → Link → document’s OneDrive URL

Copilot accepted the Reference, but subsequently responded:

“I cannot verify the title inside EU-01_01_FUNDAMENTAL.docx. The directly linked file was not returned by retrieval, so I won’t guess.”

These tests demonstrate that the proposed URL method works in some cases but fails in others, even within:

the same Copilot Notebook;

the same personal Microsoft account;

the same active OneDrive;

the same supported .docx file type;

and the same testing session.

References can therefore be accepted and displayed without becoming usable grounding sources.

2. Additional symptom: unexplained 20-item warning

Both of my Copilot Notebooks display:

“Limit reached: Copilot can chat about the 20 oldest items in your notebook.”

Microsoft’s current documentation says that Copilot Notebooks can use up to 300 files in a Notebook to generate answers:

Microsoft Support: How Microsoft Copilot Notebooks works

The successful test-folder Reference was added after the Notebook already displayed the warning, yet Copilot retrieved both test codes correctly. The warning therefore appears inconsistent with at least some of the observed behaviour and does not adequately explain why some References work while others do not.

3. Additional symptom: Copilot Notebooks missing from OneNote for Mac

Copilot Notebooks also do not appear in my OneNote for Mac application.

The installed application reports:

Microsoft OneNote for Mac Version 16.114.3 (26102720) Licence: Microsoft 365 Subscription, Microsoft 365 Premium

OneNote is signed into the same personal Microsoft account and shows the correct OneDrive – Personal connected service.

Regular OneNote notebooks are visible and work normally. They can be opened, edited, closed, and reopened successfully. My Copilot Notebooks are visible through the Microsoft web/Copilot experience, but the Copilot Notebooks section is absent from OneNote for Mac.

4. Microsoft 365 connection tests already completed

I performed the following checks to exclude a general Microsoft 365 or OneDrive synchronisation failure:

OneDrive for Mac reports “Backed up and synced.”

OneDrive starts automatically after restarting the Mac.

A Finder → OneDrive web → Finder round-trip test succeeded.

A Word for Mac → OneDrive web → Word for Mac editing test succeeded in both directions.

OneNote for Mac displays the correct Microsoft account and connected OneDrive Personal service.

Regular OneNote notebooks are visible online and can be opened and used normally in OneNote for Mac.

The same personal Microsoft account is used in OneDrive, Word, OneNote, and Copilot.

I therefore do not currently see evidence of a general OneDrive, Word, or ordinary OneNote synchronisation failure.

5. Assistance requested

The unresolved issues appear specifically related to Copilot Notebooks:

References are accepted but are not consistently indexed or returned for grounding.

The same OneDrive URL method succeeds with some folders and fails with other folders and documents.

A linked folder may be visible in References while its supported files remain unavailable to retrieval.

A directly linked supported Word document may also remain unavailable to retrieval.

The Notebook displays an unexplained 20-oldest-items warning.

Copilot Notebooks do not appear in OneNote for Mac despite the application recognising Microsoft 365 Premium and the correct account.

Could you please investigate whether this indicates:

a Copilot Notebook indexing or grounding problem;

an account entitlement or provisioning issue;

a service-side problem affecting OneDrive folder and document References;

or a related problem with Copilot Notebook integration in OneNote for Mac?

The attached screenshots show:

the 20-oldest-items warning and the current References panel;

the direct 01_FUNDAMENTAL folder Reference, Copilot’s retrieval failure, and the six Word documents visibly present in the authenticated OneDrive folder;

OneNote for Mac recognising Microsoft 365 Premium but not displaying the Copilot Notebooks section.

I would prefer not to reset, unlink, or reinstall the otherwise functioning Microsoft 365 environment unless Microsoft determines that such action is specifically required. The tests indicate that the basic account, OneDrive, Word, and ordinary OneNote connections are working.

Please let me know what additional diagnostic information is required and whether this case can be escalated for investigation of the account’s Copilot Notebook entitlement, indexing, and grounding behaviour.

Thank you for your assistanceCopilot Issues Screenshot.jpg
Carl-L 24,580 Reputation points Microsoft External Staff Moderator

2026-11-04T13:53:29.9766667+00:00

Hello Copilot Notebook User,

Thanks for replying.

I'll see what I can do. I'll keep you updated.

Also, please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas. If you need escalation, you can contact Microsoft Support or using the Feedback button on the app for more escalation options.
Carl-L 24,580 Reputation points Microsoft External Staff Moderator

2026-11-05T13:24:13.8033333+00:00

Hello Copilot Notebook User,

I've checked and it seems like this need direct look at the issue to better understand the problem. So please contact Microsoft Support to see if they are able to help or escalate the issue.

Thank you for your understanding.

Copilot Notebook: OneDrive folder reference returns “file was not found”, while individual files work

1 answer

1. Main problem: References do not work reliably

Test A: Controlled two-document folder, successful

Test B: Real project folder `00_CONTROL`, successful

Test C: Parent folder `00_EU_Normativna_ramka`, failed

Test D: Direct subfolder `01_FUNDAMENTAL`, failed

Test E: Direct document URL, failed

2. Additional symptom: unexplained 20-item warning

3. Additional symptom: Copilot Notebooks missing from OneNote for Mac

4. Microsoft 365 connection tests already completed

5. Assistance requested