lost file

I have a file with links to other files. I have been using it for several months but yesterday I was unable to load the file, that is I was unable to see the any of the file contents, no file name appeared at the top and the ribbon was greyed out. However when I closed excel it asked me if I wished to save the file.

Copying and renaming had no effect but if I found the file on "search" the contents showed in the preview panel.

Can anyone help?

Roger