Here's a weird case from a job today. Imagine you're working on your Mac and all of a sudden all of the icons on your desktop are gone! Did all your stuff just get deleted? The answer, at least in this case, is no. If you open up the Finder and look in the Desktop folder, you will see your missing files. Why are they not showing on the Desktop, you ask? Good question! What fixed it in this case was to force quit the Finder. To do this, go to the Apple Menu (top left corner of your screen), select Force Quit, click on Finder, then click on Relaunch. Finder will relaunch and poof! There are your missing files, right where they should be.