CalDav - File Not Found

I have a calender server running on os x server version 2.2.5. When one user attempts to connect to his calender it returns an error and cannot login to the server. Other users can login and get to their calendars.

From the calender error log:

[caldav-0] [PooledMemCacheProtocol,client] [twext.web2.dav.method.propfind#error] File not found: <RootResource: /Library/Server/Calendar and Contacts/Data/Documents/calendar/dav/*user*/user>

What is the best way to restore this users access to the calendar server?