title: apache not starting undefined symbol: proxy_hook_canon_handler
body: <p>Apache httpd is not starting. This is the first time I tried to start it on this particular server. I am getting the following error. </p>
  
  <blockquote>
    <p>httpd: Syntax error on line 38 of /etc/httpd/conf/httpd.conf: Syntax
    error on line 1 of /etc/httpd/conf.modules.d/proxy_connect.load:
    Cannot load modules/mod_proxy_connect.so into server:
    /etc/httpd/modules/mod_proxy_connect.so: undefined symbol:
    proxy_hook_canon_handler</p>
  </blockquote>
  
  <p>OS: RHEL 7.3</p>
  
  <p>httpd:  2.4.6-40.el7_2.4.x86_64</p>
  
  <p>apr-1.4.8-3.el7.x86_64</p>
  
  <p>apr-util-1.5.2-6.el7.x86_64</p>
  
  <p><strong>httpd.conf</strong></p>
  
  <pre><code> Security
  ServerTokens OS
  ServerSignature On
  TraceEnable On
  
  ServerName "servername"
  ServerRoot "/etc/httpd"
  PidFile run/httpd.pid
  Timeout 120
  KeepAlive Off
  MaxKeepAliveRequests 100
  KeepAliveTimeout 15
  LimitRequestFieldSize 8190
  
  
  User apache
  Group apache
  
  AccessFileName .htaccess
  &lt;FilesMatch "^\.ht"&gt;
      Require all denied
  &lt;/FilesMatch&gt;
  
  &lt;Directory /&gt;
    Options FollowSymLinks
    AllowOverride None
  &lt;/Directory&gt;
  
  
  HostnameLookups Off
  ErrorLog "/opt/www_logs/error_log"
  LogLevel warn
  EnableSendfile On
  
  #Listen 80
  
  
  Include "/etc/httpd/conf.modules.d/*.load"
  Include "/etc/httpd/conf.modules.d/*.conf"
  Include "/etc/httpd/conf/ports.conf"
  
  LogFormat "%h %l %u %t \"%r\" %&gt;s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
  LogFormat "%h %l %u %t \"%r\" %&gt;s %b" common
  LogFormat "%{Referer}i -&gt; %U" referer
  LogFormat "%{User-agent}i" agent
  LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %s %b \"%{Referer}i\" \"%{User-agent}i\"" forwarded
  </code></pre>
  
  <p><strong>/etc/httpd/conf.modules.d</strong></p>
  
  <pre><code>authz_core.load
  authz_host.load
  dir.load
  filter.load
  log_config.load
  mime.conf
  mime.load
  prefork.conf
  prefork.load
  proxy_connect.load
  proxy_html.load
  rewrite.load
  ssl.load
  systemd.load
  unixd.load
  xml2enc.load
  </code></pre>