Microsoft 365 Copilot - "Attach cloud files" fails with OneDrive File Picker ("Sorry, something went wrong")

Hello everyone,

I have been referred here by Microsoft OneDrive Technical Support after they completed their investigation.

Case number: 7106073629

The issue occurs in Microsoft 365 Copilot when using the "Attach cloud files" feature.

Instead of opening the OneDrive File Picker, it immediately fails with:

"Sorry, something went wrong.

An unexpected error has occurred."

The URL shown is the OneDrive File Picker endpoint (onedrive.live.com/picker).

The OneDrive Support team has concluded that the issue is related to the Microsoft Copilot experience rather than the OneDrive application itself and recommended that I contact the Copilot support team.

During the investigation, the following troubleshooting steps were completed:

• Tested on three different Windows 11 computers.

• Tested in Microsoft Word Desktop.

• Tested in Microsoft Word for the Web.

• Tested in Microsoft Word Safe Mode (winword /safe).

• Signed out and signed back into Microsoft 365.

• Cleared Windows Credential Manager.

• Verified OneDrive synchronization.

• Verified OneDrive Web access.

• Confirmed Microsoft 365 Apps are fully updated.

• Performed Microsoft 365 Online Repair.

The issue persists after every test.

Has anyone experienced this issue?

Could a Microsoft engineer please confirm whether this is a known issue affecting the OneDrive File Picker integration used by Microsoft 365 Copilot or whether any account-side verification should be performed?

Thank you very much.

Reference: Referred by Microsoft OneDrive Technical Support (Case 7106073629).