I am new to Lyx (and tetex). I tried to make a new document from a template. Some of the them work fine, but some come up with the error class missing. such as: The document uses a missing TeX class "elsart". LyX will not be able to produce output.
I installed the elsart.cls file in /usr/share/texmf/tex/latex/amscls/elsart.cls Tools -> TexInformation shows it there. I also did a reconfigure. -- Thomas