This occurs when a Blackbaud Sphere user was deleted and then re-added into the system.
The name of this user now appears twice within the list of Blackbaud Sphere Users in the Privileges section of the CMS site.
To resolve, have a user with Staff Privileges complete the following:
  1. Navigate to Content > Content Management System 
  2. Hover over the website name and click on Manage Website
  3. Click on the Administer tab
  4. Click Privileges
  5. Click Staff Privileges
  6. Click Update above the list of Sphere Users.
This should prompt the information to refresh.
Once this has been done, the user can go into the Website Privileges section and add the individual back into the list of users who are allowed to Create, Edit, Publish, etc.