Comment 2 for bug 1733125

I'm experiencing the same problem.

Was running standard Ubuntu 17.10 with gnome. Wanted to try out openbox.
Ran 'sudo apt-get install openbox obconf'
Logged out, restarted, logged in.

Haven't spent much time on it because of the window issue.
Have noticed I also get an error box "Invalid output from pipe-menu -i lxde-applications.menu" when I pull up the right click menu and move the mouse to "Applications".