xfce4 loses title bars on all windows I'm running `Debian Wheezy` using `gdm3` as window manager and `xfce4` as desktop environment. Every so often, when I login, the desktop environment starts OK, but all windows are missing the title bar and are positioned at location (0,0). Usually logging out and back in, or restarting `gdm3` and logging in, fixes it, but today it didn't. I switched to 'GNOME classic' which works fine, indicating it's probably a setting in `xfce4` that's got corrupted. Short of just zapping every file in `.config/` and `.cache/` which refers to `xfce`, is there a simple fix/edit?

Xfce's window manager crashed for some reason and the simple fix is to run `xfwm4` in a terminal.

If you can't do it in X (because, e.g., the panels/menus are unavailable, Alt+F2 doesn't work), switch to a virtual console (e.g. Ctrl+Alt+F2), login, and type `DISPLAY=:0 xfwm4 --daemon`.

(Use Ctrl+Alt+F7 to switch back to X.)