Translation:This TV show is not that interesting.
テレビ can also be an abbreviation for TV program, TV programme, TV broadcast and at least in US (I think) TV show.
It only accepts the abbreviated 'TV program', which grinds my gears just a little. Surely 'television program' should be an acceptable term. However, I do admit 「テレビ」is itself an abbreviation of 「テレビ番組」... Perhaps that's why?
TV vs TV show? In this case I think we all know that they meant TV show, but isn't this literally just TV? What if I'm comparing two tvs in conversation and then use this sentence? I would have meant the physical tv right?
I think it would have been better for Duolingo to have said テレビばんぐみ（番組）rather than just テレビ for TV show. Though they may be cases where you might describe a physical television set as interesting, from the context people would probably assume you meant the TV program.
面白い= 1. interesting; fascinating; intriguing; enthralling 3. pleasant; enjoyable; agreeable; fun.
余り=not very; not much.
So "This TV show is not much fun." should also work.
As Matas said, the ない is technically a verb in plain (casual) form. You could put a です after おもしろくない to make it polite (though technically です isn't a verb). It does seem strange that in all (or most?) other sentences on Duolingo they are teaching the polite form using です and ます.
i am confused about this whole course , isnt this supposed to be a feelings course? none of these sentences except for a few seem to fit the label. how is this tv show is not that interesting a feeling.
Feeling uninterested by the tv program is a feeling. But this course has angered you.. so the feeling part got through xD
Kono telebi no bangumi wa omoshiroku nai. Bangumi is program and this word is not in the sentence.
Got marked wrong for “This TV show is not much interesting.” Reported. -.-