(A) Had Folder(1) which did not allow name changing, "because open document". Closed "document" but did not allow name changing.
Next day, same thing. Changed Folder1 icon to "forbidden sign icon"
B Then copied Folder(1) Inside brand new NewNameFolder(2)
C Made sure both had same size (with F5)
D Deleted Folder1 permanently with Shft-Del
E The copy of Folder(1) inside Folder(2) also was deleted.
Everything was lost! SOS!