Resolve Integrated Shipping Authentication Failure After Sandbox Refresh

After a sandbox refresh, a user may receive the following notification when calculating shipping on a sales order:  'Could not calculate cost for selected real-time rate. Authentication failed.'

This error can be resolved by taking the following steps to simply reset carrier registration:

1. Navigate to Setup > Accounting > Shipping.
2. Under the Carrier Registration tab, delete the carrier that is causing the authentication failure. Be sure to record existing carrier information including important account numbers.
3. Add the carrier once again and fill in all previously recorded information.
4. Click Submit.

After successful submission, the notification should disappear.