thanks. I then tried a workaround, but I’ve got a bizarre result. The following C# code (specific for the Italian version of Rhino) deletes all linetypes but the continuous.
RhUtil.RhinoApp().RunScript("-_DocumentProperties t e “Bordo” e “Centro” e “Nascosto” e “Punti di annotazione” e “Tratteggiato” e “TrattinoPunto” INVIO INVIO");
By itself it works, but when I integrate it into my specific start-up code, which is called at Rhino start-up and which first of all opens a default document and then tries to customize the linetypes, it fails.
It looks like if Rhino is restoring the line database in parallel during my startup plugin. Is it possible?