I was following the Zabbix installation tutorial for Ubuntu and it requested that I added a file /etc/apache2/sites-enabled/000-default containing

Alias /zabbix /home/zabbix/public_html/
<Directory /home/zabbix/public_html>
  AllowOverride FileInfo AuthConfig Limit Indexes
  Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec
  <Limit GET POST OPTIONS PROPFIND>
    Order allow,deny
    Allow from all
  </Limit>
  <LimitExcept GET POST OPTIONS PROPFIND>
    Order deny,allow
    Deny from all
  </LimitExcept>
</Directory>

But I already have /etc/apache2/sites-enabled/railsapp

NameVirtualHost *:80
NameVirtualHost *:443

<VirtualHost *:80>
    UseCanonicalName Off
    Include /etc/apache2/conf/railsapp.conf
</VirtualHost>

<VirtualHost *:443>
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/cert.pem
    Include /etc/apache2/conf/railsapp.conf
    RequestHeader set X_FORWARDED_PROTO 'https'
</VirtualHost>

and /etc/apache2/sites-enabled/mercurial

NameVirtualHost *:8080

<VirtualHost *:8080>
    UseCanonicalName Off
    ServerAdmin  webmaster@localhost
    AddHandler cgi-script .cgi
    ScriptAliasMatch ^(.*) /usr/lib/cgi-bin/hgwebdir.cgi/$1
</VirtualHost>

I think that it is because of the already existing virtual hosts that my I can't access the zabbix page. How to circumvent this?