If you are trying to embed Jenkins page in another page then you might get following exception:
Refused to display http://localhost:8080/jenkins in a frame because it set ‘X-Frame-Options’ to ‘SAMEORIGIN’
It’s refused because X-Frame-Options HTTP response header is set to SAMEORIGIN to avoid clickjacking attacks, by ensuring that content cannot embedded into other sites.
If you are facing the same problem as me then you can fix it restarting the Jenkins setting the system property -Djenkins.security.FrameOptionsPageDecorator.enabled as false from Jenkins 1.581, as follows:
java -Djenkins.security.FrameOptionsPageDecorator.enabled=false -jar jenkins.war
Along with setting the ALLOW-FROM uri in a page where you want to embed Jenkins page.