One-line summary:
The OneDrive file picker in Copilot consistently displays "unauthenticated" and cannot access my files, even though OneDrive itself works normally across all platforms.
Detailed explanation:
I am experiencing an account-specific issue with the Copilot file picker. When I attempt to browse OneDrive files from within Copilot, the file picker loads but displays an "unauthenticated" error and no files are shown. I have confirmed that the issue is not related to the device, browser, or Copilot application because the exact same environment works correctly when I sign in with a different Microsoft account. Additionally, my affected account functions normally in OneDrive Web, OneDrive Desktop, and OneDrive Mobile, including file access and uploads. I have already performed extensive troubleshooting, including signing out and back in, clearing cache and cookies, using private browsing, resetting and reinstalling Copilot, testing multiple browsers and devices, and signing out of all Microsoft sessions. Since the problem follows only this specific Microsoft account across both Copilot Web and the Copilot App while all other OneDrive services continue to function normally, the issue appears to be related to the Copilot-to-OneDrive authentication, authorization, or account provisioning configuration on the backend.