I’m running Windows 10 developer preview 10130, but I had this problem on a previous build, too. (It went away when I upgraded to a new build, but now it’s back again.)
Atom was running fine on Windows 10, but all of a sudden, when I open existing files (txt, py, html, js, sql, you name it) from the directory tree in Atom’s left pane, the files open empty. I can type stuff into them and the stuff I type shows up, but the original contents are missing.
If, however, I open the same files directly from Windows 10, right clicking on them in File Explorer and telling File Explorer to open the files in Atom, the files open properly in Atom.
I expect it’s a Windows 10 issue that won’t be supported here, but any thoughts on a workaround? Is this a know issue Atom has with other versions of Windows too? I don’t experience it in other apps running on Windows 10, but then again I’m not running many other apps . . .