I am trying to prepare a document in the lipics-v2016 template. It can be downloaded from here: https://www.dagstuhl.de/en/publications/lipics/instructions-for-authors/
I tried compiling the lipics-v2016-sample-article.tex file, which is available in the above link. (I use the editor Tex Shop on macOS Sierra.) I keep getting the error, "you haven't specified the language option".
I don't know how to rectify this.