Impossible to watch videos on the NBC website I am trying to watch Saturday Night Live on the nbc website, but no matter what browser I try (Safari, Chrome, Firefox), or what computer I try (iMac with El Capitan, MacBook Air with macOS Sierra), I get the exact same message:


Sorry, we can't play this video in its intended experience because we're unable to load the accompanying message from our sponsors.

I have the latest version of Flash, there is no VPN or AdBlock installed on the MacBook Air and on the iMac's Firefox and Chrome.
A message bar appeared in Firefox indicating "Firefox disabled Flash for this website" so I allowed it. Didn't make a difference. I also tried checking the browsers' preferences, as well as the Macs' System Preferences, but couldn't find anything that would prevent videos from working. I've looked for answers online but couldn't find any.

Every other website I use to watch videos (YouTube, Vimeo) work well. 
Some Flash-based websites require two permission steps to start displaying Flash content, for example here is Nitrome:



Step 1



Step 2

But the NBC website doesn't ask this.
To reproduce, go to this link and click any video in the "Episodes" section.

What is causing this issue and how can I fix this?
I actually was having the same problem, for me it turned out to be that my /etc/hosts file was blocking certain hosts and adservers that the nbc.com site wanted to reach. So I just renamed my hosts file and restarted mDnsResponder.