Dear, I will try to clarify with a video.
Please, could you see it here? https://www.dropbox.com/s/61sb07hx4stvbcs/mutt-file-not-open.mp4?dl=0 In this video, I did: Opem mutt, go to message, open the attach view, hint the attach file. After, I close de evince and hit I to return to page. Any clue? -- Marcelo