When users have issues with the "print" or "close" button, it's almost always an issue around having a pop-up blocker enabled on their browser.
To check if you have a pop-up blocker enabled (and to disable it), go to the Settings of your browser, and look for the Privacy settings in particular. Disabling the pop-up blocker should resolve this issue.
Still have questions? Please email us at firstname.lastname@example.org.