"It appears as though you do not have permission to view information for any of the services you requested...
If you believe this is an error, check the HTTP server authentication requirements for accessing this CGI
and check the authorization options in your CGI configuration file."
 
sdfsyou  get this error if you changed your nagiosadmin user name to the name you wished, or you  misconfigured htpasswd.users file's default directory, becauser they both are preconfigured in /usr/local/nagios/etc/cgi.conf  and /etc/httpd/conf.d/nagios.conf files. So if you want to take a chance to modify them or else create htpasswd.users file with default path and username carefully.