I want to do a little reorganising of a project, and this includes dropping certain stories and notes for stories and so on into folders. But “New folder” and also “New text” (is that new document?) are greyed out. How can I bring them back from the dead? (And usedn’t they be in the File menu item?)
Screenshot of the menu attached.
Hi.
These are usually greyed out when the focus/position is somewhere relative of which a new file or folder can’t be inserted.
For example, the trash bin.
Just make sure the focus is on the binder, selected be the file/folder above where you want the new item inserted. Or have the focus on the editor (normal view/text view), the new file/folder will be inserted after the file displayed.
It is only a matter of Scrivener knowing where to insert it (say the focus is on the editor, outline view, no item selected: won’t work), and/or the operation making sense. (No point inserting new files to the trash.)
Your screenshot shows that you are currently fine. 
To put it simply: unless you used navigation, the focus is on the last section of the interface (binder, editor, …) you interacted with.
That’s the way it was the whole time!
Oddly, the shortcuts seem to be working now, though they’re still greyed out.
I believe that the shortcuts being greyed out is a Mac visual thing.
But if you look at your screenshot from when it didn’t work, you can see that the menu function’s name was also greyed out, where it is black in your last one.
That’s right! Mysterious!