RESOLUTION 1:
If you do have another Spotlight Diagnostic Server installed using this key; disable the Spotlight Diagnostic Server service on the previous install and then try restarting the service on the one you need active.
RESOLUTION 2:
To grant permission to the Diagnostic Server (DS) user to the registry for Spotlight:
1. To open the Registry Editor.
2. In the left pane, right-click on HKEY_LOCAL_MACHINE | Permissions...
(NOTE: That same will be done for HKEY_CURRENT_USER).
3. Select the group or user name where the permission needs to be applied.
4. Select the Allow check box for the access levels of the group or user name.
Read - permission to read the key contents, but not save any changes
Full Control - permission to open, edit, and take ownership of the key
(We need the 'read/write' permissions)
5. To grant special permission in the key, click Advanced.
6. Under Permissions, double-click the user or group where the special permission needs to be applied.
7. On Type drop-down menu, select Allow or Deny for the permission.
8. Click on the Show advanced permissions to expand the permission options.
9. When you have completed your changes, click Apply and then OK to accept them.
