Now I use Circuit Studio for ecad.
I downloaded AM571x Industrial Development Kit(IDK) Gerber Files — SPRCAG3.ZIP (8971 KB)(https://www.tij.co.jp/jp/lit/zip/sprcag3),and tried to open Gerber File(file extension：.art).
But I could not open it.
Like attached file,only show text.(Correctly I think I can see PCB pattern like a picture.)
Could you tell me what to do if you know.