"If HC Andersen were alive today, he would be over one hundred years old." (which makes grammatical sense) is accepted. I can't say if the Danish sentence is grammatical, but it doesn't look right to me.
I reported it. However the report options do not offer "the English sentence does not make sense" and they don't have the free line any more to describe the fault. So I put an (X) to all the fault categories.