My laptop worked fine earlier today, but just now I started it up and logged in, but my desktop is empty, my panels/toolbars/status bars are gone, and while I can move the mouse, right-clicking does nothing. I've rebooted several times (selecting both Xubuntu and XFCE sessions at login) and the problem persists. Xmonad sessions seem to start normally, though (I only vaguely know how Xmonad is supposed to work, though, so I only tested basic features ).
I just had this same problem and solved it by removing my ~/.cache and ~/.config/xfce4-session folders. After that I just ran 'service lightdm restart' so it would repop the session choices and my normal Xfce desktop was there.
Try this command, it worked for me: