Where did all the places from Finder on macbook go on the left?

Question

macOS

When I called the "upload file" menu, both my macbook and the girl on the macbook lost references to the desktop, downloads, etc., and everything looks like this.

If I put them there, they disappear again on the next boot. How to fix?

Answer 1

This is a glitch in 10.11, sometimes links disappear. Reload Finder from the console:
killall Finder
and everything returns. Or just reboot.