It would be nice if apache told you which module you were missing. Fortunately, there’s the Internets! Hey, this site is on the Internets let’s see if we can help. I just ran ‘service httpd checkconfig’ and received the following error:

# service httpd configtest
Syntax error on line 92 of /etc/httpd/conf/httpd.conf:
Invalid command 'Order', perhaps misspelled or defined by a module 
not included in the server configuration

After a brute force attempt at adding modules, it became clear that I was missing the following module: authz_host_module. I added that in httpd.conf with the following directive:

LoadModule authz_host_module modules/mod_authz_host.so

You can also compile that module into the binary with the following flag: –enable-authz-host  (in most cases that’s compiled by default but I’m using RedHate’s binary so it was necessary to add it at run time).