It appears as though you do not have permission to view information for any of the hosts 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.
修改/etc/cgi.cfg
vi /usr/local/nagios/cgi.cfg
use_authentication=1 #把1修改为0,保存
root@nagios#/etc/init.d/nagios restart
转载自：http://cqfish.blog.51cto.com/622299/150542