The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a iframe, If not permitted this will make your iframe page white.

For Configuring Apache

You must add this code to .htaccess

<IfModule mod_headers.c>
	Header unset X-Frame-Options
	Header always unset X-Frame-Options
	Header set X-Frame-Options "ALLOWALL"
</IfModule>

For Configuring nginx

To configure nginx to send the X-Frame-Options header, add this either to your http, server or location configuration

add_header 'X-Frame-Options' 'ALLOWALL';

For Configuring IIS

To configure IIS to send the X-Frame-Options header, add this to your site's Web.config file:

<system.webServer>
  ...

  <httpProtocol>
    <customHeaders>
      <add name="X-Frame-Options" value="SAMEORIGIN" />
    </customHeaders>
  </httpProtocol>

  ...
</system.webServer>