Chrome: An additional plug-in is required to display some element.

What plug-in should I install? How can I look at the installed plug-ins?

You can look at the installed plug-ins by typing in the Chrome browser:
about:plugins or chrome://plugins/

When I click on "Install plug-in" nothing happens.


In this case, there is chance that you are suffering from Skype plug-in:


Refer to:Chrome–An additional plug-in is required to display some elements on this page–Solved

I fixed my Chrome by removing Skype extension.