Access denied to file shared via Teams chat

Question

Access denied to file shared via Teams chat

Joachim Denk 20

Hello,

I'm global admin of an M365 Tenant and I have two users with file sharing problems.

User A sends a file via simple Teams chat to User B, but when User B tries to open the file, he gets the error of access denied.

Both users are normal internal members of the M365 Entra ID Tenant.

I already investigated the Purview Audit Logs, but can't find any helpful entries.

Can I somewhere enable detailed logging, which could help me to find the problem?

Thx
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Answer 1

Sophie N 8,095 Microsoft External Staff Moderator

Dear @Joachim Denk,

Thank you for posting your question in the Microsoft Q&A forum reaching out about the file access issue in Microsoft Teams. I understand you're facing an "Access Denied" issue for files shared in a private Teams chat, even between two internal users. This is a common issue, and I apologize for the frustration.

This problem is almost always related to the file's underlying permissions in OneDrive/SharePoint than a Teams setting.

To help me narrow down the cause, could you please provide the following details?

Have both users confirmed they are part of the same organization and have been added to the Teams environment?
Are there any specific permissions set on the OneDrive/SharePoint files that might prevent access for the other user?
Could you clarify whether the issue occurs with other files shared in Teams, or is it isolated to specific files?
Have the users attempted to access the files using a different device or browser?

In the meantime, please try the following official troubleshooting options which usually resolve issues with basic issues:

As a global admin, you can troubleshoot this by checking the following areas:

Option 1: Sharing Settings:

Verify the file’s storage location (usually SharePoint). Ensure the sharing settings for the associated SharePoint site allow internal users to access files.
Navigate to the SharePoint Admin Center > Policies > Sharing and confirm that sharing is enabled for internal users.

Option 2: File-Level Permissions:

The file might have unique permissions restricting access. Check the file’s permissions in SharePoint:
Go to the document library where the file is stored, select the file, and review its permissions under the "Info" pane or "Manage Access."

Option 3: To fix this issue, deactivate this feature in OneDrive.

Sign into your OneDrive site.
Select the Setting icon in the upper-right corner of the screen.
Select OneDrive Settings > More Settings.
Under Features and storage, select Site Collection Features.
Locate Limited-access user permission lockdown mode, and then select Deactivate.

User's image

For more information about Limited-access user permission lockdown mode, see Enable or disable site collection features - Microsoft Support

Common Fixes:

Ask User B to try opening the file in a web browser (via SharePoint) instead of the Teams app.
Ensure both users have valid Microsoft 365 licenses and are not restricted by conditional access policies.

For step-by-step guidance, refer to this Microsoft documentation:
Error (You don't have access to this file) when opening a file in Teams - Microsoft Teams | Microso…

If the issue persists, please provide additional details, such as whether the file is stored in a private or shared channel, and any recent changes to tenant policies.

We’re here to help further if needed!

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread. User's image

Sophie N 8,095 Reputation points Microsoft External Staff Moderator

2025-10-27T02:33:18.12+00:00

Dear @Joachim Denk,

I hope you’re doing well. I just wanted to check in and see how things are going with the steps I shared earlier. If you ran into any difficulties at any point or if something is unclear, please don’t hesitate to let me know. I completely understand that these processes can sometimes be tricky, and I’m here to make it as easy as possible for you.

Feel free to share any details or questions you might have, I’m ready to listen and assist you further.
Joachim Denk 20 Reputation points

2025-10-27T13:15:37.98+00:00
Hello Sophie,

unfortunately I couldn't solve the problem.

answers to your questions:

To help me narrow down the cause, could you please provide the following details?

Have both users confirmed they are part of the same organization and have been added to the Teams environment?

Are there any specific permissions set on the OneDrive/SharePoint files that might prevent access for the other user?

Could you clarify whether the issue occurs with other files shared in Teams, or is it isolated to specific files?

Have the users attempted to access the files using a different device or browser?

I as global admin I can confirm that both users are part of the same organization and have been added to the Teams environment.

There are no specific permissions set on the OneDrive/SharePoint files that might prevent access for the other user.

It's specific to users and not to files. Some users can share files with User B and some not.

The access with different browser (also incognito mode) didn't change anything.

There is one thing to mention which could be interesting:
The M365 Account from User B was deleted (not only deactivated) 1.5 years ago and newly recreated with the same UPN starting this year. Perhaps there is now a kind of ID mismatch somewhere internally Entra ID.

All of your other official troubleshooting recommendations didn't help anything.

Thx

remove pii
Sophie N 8,095 Reputation points Microsoft External Staff Moderator

2025-10-28T05:29:45.34+00:00

Dear @Joachim Denk,

Thank you for the critical detail about User B's account being deleted and recreated with the same UPN. This confirms the likely cause: a User ID Mismatch between the new account in Entra ID and legacy references in the SharePoint environment.

When a user is deleted and recreated, they receive a new unique identifier (Passport GUID). However, files shared by certain users may still be associated with the old, invalid GUID, causing the "Access denied" error.

Please follow this targeted procedure to resolve the ID mismatch. This solution is based on the official Microsoft troubleshooting guide for this specific scenario: Fix site user ID mismatch in SharePoint or OneDrive - SharePoint | Microsoft Learn

Please try step by step of article under admin center to review this issue

This process forces SharePoint to update its internal user mapping, reconciling the new user identity with the files shared in Teams. The issue should be resolved for new file shares after this sync.

After the admin tests the above step, please wait for about 1 hour. Then, ask the user to close the browser completely and clear the cache. Then, re-share the original link or send a new share link so that the user can check again.

If the problem persists after completing these steps, we recommend opening a service request with Microsoft Support. At that point, support engineers can examine backend logs to investigate any remaining hard-coded permission references.

I hope this information helps you resolve this quickly. Please let me know if you have any further questions.
Sophie N 8,095 Reputation points Microsoft External Staff Moderator

2025-10-29T02:37:35.33+00:00

Dear @Joachim Denk,

I hope you’re doing well. I just wanted to check in and see how things are going with the steps I shared earlier. If you ran into any difficulties at any point or if something is unclear, please don’t hesitate to let me know. I completely understand that these processes can sometimes be tricky, and I’m here to make it as easy as possible for you.

Feel free to share any details or questions you might have, I’m ready to listen and assist you further.
Sophie N 8,095 Reputation points Microsoft External Staff Moderator

2025-10-31T03:18:51.3533333+00:00

Dear @Joachim Denk,

I hope this message reached you.

This is my second time reaching out to check if your issue has been resolved. I really want to make sure your experience is as smooth as possible. If your issue persists or if you encounter any new difficulties, please share more details about the current steps you are taking. I am always happy to assist you whenever you need.

While waiting for your response, I will also be monitoring other customer questions on the forum to assist them. If you have any further questions or updates, please tag (@Sophie N) in the reply so I can assist you more promptly and thoroughly.

I look forward to hearing from you soon.
Joachim Denk 20 Reputation points

2025-11-03T15:01:09.33+00:00

Thx.

The hint with the ID mismatch fix solved my problem.
Sophie N 8,095 Reputation points Microsoft External Staff Moderator

2025-11-03T23:25:21.4033333+00:00

Dear @Joachim Denk,

Thank you for letting us know, I'm really glad to hear that the ID mismatch fix resolved your issue!

If you have any other questions or run into anything else, please don’t hesitate to post again in the community. I’d be more than happy to assist you further.

Wishing you smooth sailing from here on out!

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Access denied to file shared via Teams chat

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