Youtube Unavailability : Message on-screen
Issue
It has been noticed that some NetCast Smart TVs have just been recently experiencing YouTube service disruption as identified by this on-screen message “YouTube is unavailable” as illustrated below :

After having selected YouTube application to stream content, this message appears leaving the TV in complete limbo.
We are terribly sorry for the inconvenience. Engineers are working around the clock along with Google/YouTube software engineers to resolve this unfortunate situation.
Google/YouTube did mention they will rollback their server on June the 3rd at 2:00am Korea time.
There is no certainty that said action will fix the issue. However, should it not be the case, we are confident a solution or fix will prevail fairly shortly and YouTube streaming resume very shortly.
Please bear with us during this temporary crisis. Again, so terribly sorry for the inconvenience this is causing you.