I am also experiencing this issue, ironically also using HI-DPI skin for XFCE4, maybe something about that? A few of the buttons I have found are simply hidden, like they have rescaled under the UI and you can simply pull it up with a mouse click when it turns into a little arrow. But as for the actually installer page, or in your case shortcut creator, I cannot figure this out.
ACTUALLY YES, it is the HI-DPI window manager theme. I turned that off (changed it to greybird), and after closing and opening the window missing the UI elements they now suddenly appear. Best action seems to be changing this, do what you wanna do and then set it back
Editiert von: Trist