When plotting "points" data files from fupermod, you will need this: set datafile missing "."
Error message "';' expected"
That syntax (linetype specification with just a number, but no keyword) has been deprecated for several years now. It had never been an officially documented feature anyway, and was removed ages ago. Have a look at "help plot style" to see how it's done. More
plot with lines 1
plot with lines ls 1