Symptoms

Site URL ? is already registered with this title. Duplicate SharePoint group providers are not allowed. Either remove the current SP group provider if it is no longer needed or change the title of this site collection.Logged : True

 

Diagnoses

Duplicate entries were appearing in the HostServer.GroupProvider table.
 

Resolution

Updated the HostServer.GroupProvider table by removing and renaming items that were causing the conflict which allowed the registration to complete and create new smart objects for the site