Error On Deployment

ItemNotFound

{
  "error": {
    "error": {
      "code": "itemNotFound",
      "message": "The resource could not be found."
    }
  }
}

This usually means BASE_DIRECTORY does not point to an existing OneDrive folder.

Check these items:

1. The folder exists in the OneDrive account configured by USER_PRINCIPAL_NAME.
2. BASE_DIRECTORY starts with /.
3. The OAuth account is the same account that owns or can access that folder.

403 After Deployment

The app cannot find valid OAuth tokens yet, or Redis is unavailable.

Check these items:

1. REDIS_URL exists in Vercel production environment variables.
2. The project was redeployed after REDIS_URL was added.
3. OAuth setup was completed on the deployed site.

Upload Permission Denied

This happens when the stored OAuth token does not include write permission.

Error 504

504 errors are usually caused by a slow Microsoft Graph response, an invalid Redis connection, or a folder traversal that is too large for a serverless request.

Check REDIS_URL, retry the request, and avoid using folder zip download for very large folders.

API fetch error

Error message:

Failed to refresh Microsoft Graph API access token. Reset OAuth tokens and authenticate again

This happens when the stored Microsoft Graph access token or refresh token is invalid. Common causes:

• Access token expired and the refresh attempt failed
• Microsoft account password was changed
• Authorization for VercelDrive was revoked in the Microsoft account
• Azure App Registration was deleted, changed, or broken
• Stored tokens in Upstash are stale

Fix

Step 1: Check your Microsoft Entra App Registration.

Open Azure Portal — App registrations and verify the app used by VercelDrive still exists and is correctly configured. If the app registration was deleted or its configuration changed, recreate it and update the Vercel environment variables:

• CLIENT_ID
• CLIENT_SECRET

See Advanced — Microsoft Entra App Registration for setup details.

Step 2: Clear stored tokens in Upstash.

1. Open the Upstash Console: console.upstash.com
2. Select the Redis database connected to your VercelDrive project.
3. Open Data Browser.
4. Find and delete these keys:
   • access_token
   • refresh_token
   • If you use KV_PREFIX, delete <KV_PREFIX>access_token and <KV_PREFIX>refresh_token instead.
5. Use the ... menu next to each key and choose Delete Key.

Step 3: Redeploy.

1. Open your Vercel project dashboard.
2. In the sidebar, open Deployments.
3. Find the latest Ready deployment.
4. Hover the ... menu on the right and choose Redeploy.

Step 4: Authenticate again.

After redeployment, open your site. VercelDrive will show the OAuth setup wizard. Complete the 3-step authentication flow to store fresh tokens.