Troubleshooting

Common issues and how to fix them.

OAuth redirect URI mismatch

Symptom: After signing in with Microsoft, you see an error about redirect URI mismatch.

Fix: In your Azure App Registration, set the redirect URI to http://localhost (exactly). VercelDrive uses this value during the OAuth flow.

Missing or incorrect REDIS_URL

Symptom: The site shows 403 after deployment, or OAuth tokens are not saved.

Fix:

1. Connect an Upstash Redis database in Vercel Storage.
2. Confirm REDIS_URL is set in production environment variables.
3. Redeploy after adding the variable.

Upload permission denied

Symptom: Upload fails with “Microsoft Graph denied upload access.”

Fix:

1. Add Files.ReadWrite.All delegated permission in Azure.
2. Grant admin consent if required.
3. Clear stored tokens from Redis (access_token and refresh_token).
4. Redeploy and authenticate again.

See Token reset for detailed instructions.

Stale OAuth tokens after changing permissions

Symptom: The site behaves as read-only even after adding Files.ReadWrite.All.

Fix: Changing permissions does not update stored tokens. Clear the old tokens and re-authenticate. See Security — Token reset.

Wrong BASE_DIRECTORY

Symptom: “itemNotFound” or “The resource could not be found.”

Fix: Confirm the folder exists in the OneDrive account, starts with /, and the OAuth account has access to it. See Error on deployment.

OneDrive folder path not found

Symptom: 404 when browsing a specific folder.

Fix: OneDrive paths are case-insensitive but must match the actual folder structure. Check for typos, extra spaces, and encoding issues in BASE_DIRECTORY.

Accidental NEXT_PUBLIC_ exposure

Symptom: A secret variable is visible in browser devtools.

Fix: Remove the NEXT_PUBLIC_ prefix from any variable that contains a secret. Only NEXT_PUBLIC_SITE_TITLE, NEXT_PUBLIC_PROTECTED_ROUTES, and NEXT_PUBLIC_EMAIL should use this prefix. See Security — Environment variable security.

Microsoft Graph token refresh failure

Symptom: “Failed to refresh Microsoft Graph API access token.”

Fix: See Error on deployment — API fetch error for step-by-step recovery.