Fix iCal errors, display issues, and buttons that don't work in Yahoo Calendar

If you're having problems adding your Yahoo Calendar to a mobile device or an application like Apple Calendar or Mozilla Lightning it's usually related to the iCal address. Most feature problems, like buttons not working or display errors, can be resolved with some general browser maintenance.

Unsupported devices

If your device doesn't support CalDAV (iCal), you can access your Yahoo Calendar using a mobile browser at

Resolve error messages

"Server authentication error"

If you're unable to sync your Yahoo Calendar to a device or application, the server name or login info may be incorrect.

  • To fix this issue, enter the correct server name in your calendar tools settings:
    Correct server name:
  • Verify your login info works. Try to sign in to your Yahoo Mail account on a computer.
  • If your password includes special characters (like '#' or '$'), change your password to exclude them, then update your password on the device, and attempt to reproduce the issue.
  • If you're using an iOS device, try to sync your account with the Setup Wizard. 

"Please enter a valid iCal address"

This error occurs when the iCal address you're trying to subscribe to doesn't begin with "http://". To fix this, you need to adjust the iCal address you are subscribing to using the steps below'

  1. In the iCal Address field, replace "webcals://"  with "http://" in the URL.
  2. Check that all of the settings are correct for your calendar.
  3. Click Continue.

Note: If you receive "Error code: 500" when you try to add a calendar with an iCal address, check with the calendar owner to make sure you've entered the URL correctly.

Navigation and display issues

Yahoo Calendar is a browser based application. Problems with buttons, page loading, and drop-down menus can usually be resolved with general browser maintenance