It's quite like this question. But there is a little bit difference.
In my situation, all files and folders in the Desktop were disappeared. And when I right clicked on the desktop, the drop-down box didn't appear. Whatever operation I did, nothing happened.
But when I opened the
home folder, and access the
desktop folder from it, files and folders were there. And I could operate the files as usual.
So I wonder how to get my files and folders back to the Desktop.