Recovery mode: "You can't change the startup disk to the selected disk"

In recovery mode now. Each time I've tried to reinstall the OS, there's no disk listed as a choice. The box is blank.

I have a MacBook Air, basic, a few months old. The product specs and OS version numbers aren't available at the moment (due to recovery mode?). There are no files on it I would be devasted to lose.

Has anyone encountered this before? Does anyone have ideas for a next step? Any insights appreciated!

(I've searched a couple support communities on this site, and while I did finally come across a similar question, there were no answers.)