"I am not an artist."
Translation:Nem vagyok művész.
It's as if you wrote muvesh, to get an s in Hungarian you're supposed to write sz: Művész.
I'm not sure how Duolingo's testing engine works, but maybe they were too strict on this one. Are you sure you got the phonetic chars right i.e. művész and not muvesz? Maybe you wrote muves with a single s?