Redmine

https://www.google.com/search?q=X-Frame-Options+apache

Thank you Toshi for the very fast response, but we are using Thin and Nginx. There is no X-Frame-Options option in our nginx.conf, and so it must be Thin or Ruby Rails? We think the thin config file is /etc/default/thin but there is also no X-Frame-Options in it. So it must be Ruby Rails? Can you advise us where the config file for Ruby Rails is located so that we can remove the X-Frame-Options ? We are not familiar with Ruby at all. We googled for information but still cannot figure out how to configure Ruby to remove the X-Frame-Options. It is not in config/application.rb. Thank you once again.

[[http://techqa.info/programming/question/13929693/thin-web-server---x-frame-options-configuration]]

[[https://coderwall.com/p/2d0phq/rails-4-allow-your-site-to-be-iframed-by-another-site
]]

Please ask Thin or Nginx or Rails community.
Or you can modify this file.
source:tags/3.3.3/app/views/layouts/base.html.erb