This was an interesting one that took a bit of head scratching and may be useful. It was for a client that we provide IT support in Letchworth.
The client was opening a shared spreadsheet. The file would open, but the excel screen remained blank. You could not see any tables at all. This was Excel 2007 but may be applicable to other versions. It only affected this single user.
It turned out they had somehow managed to push the sheet off-screen – Going into ‘view’ and hitting ‘full screen’ bought the spreadsheet back into view, but it disappeared again when exiting full screen.
Going then to window>tile bought it back into the normal pane, and after resaving it opens normally.