MSFT Teams, Clicked on OneDrive and received a 404 FILE NOT FOUND Error -> What is the cause and the fix?

Question

I recently added a domain and made that domain primary on email. Now when I log into Microsoft Teams, and click on the OneDrive App, I continuously receive a 404 FILE NOT FOUND error.

Tests I have been trying:

1. Can I get OneDrive to work from edge? Yes. When I goto OneDrive.com, and log-in with my new email address (containing the added domain name), I can view my OneDrive, but if I am within Microsoft Teams, I receive the error.
2. Do others apps added within Microsoft Teams error? No. This is good news. I have successfully opened, Word, Powerpoint, Excel, and there is no issue...it is just OneDrive.

Ideas on what I can do to fix this? It is impacting my teammates as well.

Answer 1

Dear @Roots&Helixes,

Thank you for posting your question in the Microsoft Q&A forum.

Based on your description, after changing the primary domain/UPN, OneDrive works in the browser but shows 404 File Not Found when accessed from the OneDrive app in Microsoft Teams.

Could you please confirm that are multiple users affected, or only specific accounts?

In the meantime, here are some suggestions you can try:

Trigger OneDrive access (file upload or Files tab)

Sign out of Teams

Close Teams completely

Reopen Teams and sign back in to check whether the issue still persists or not. Expect OneDrive URLs to change. Sync clients usually auto-update, but users may need to restart the sync app.

Validate DNS and Identity

Update DNS records (MX, SPF, DKIM, DMARC) for the new domain.

Verify Entra ID (Azure AD) and Conditional Access policies.

For more information, you can refer to this article

How UPN changes affect the OneDrive URL and OneDrive features

"404 File not found" error when accessing the OneDrive app in Teams

Please let me know if this helps resolve the issue. If it doesn’t, feel free to leave a comment below so we can work together to find a better solution.

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Answer 2

The 404 FILE NOT FOUND error you are encountering when accessing the OneDrive app in Microsoft Teams is likely due to a change in your User Principal Name (UPN) after adding and making a new domain primary. When the UPN changes, it can lead to issues accessing OneDrive within Teams, resulting in this specific error message.

Fix:

To work around this issue, you can follow these steps:

1. Start a one-on-one chat with another user in Teams.
2. In the compose box, select Actions and apps > Attach file > Upload from this device.
3. Choose a file to send and click Open.
4. Select Send.
5. After sending the file, navigate to the OneDrive app from the left navigation bar in Teams.

This workaround should help you access OneDrive in Teams until a more permanent fix is implemented.

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References:

• 404 File not found error when accessing the OneDrive app in Teams
• How UPN changes affect the OneDrive URL and OneDrive features