Linux - problema menu openbox lubuntu

buon giorno, ho un problema con lubuntu perche volgio mettere il menu di lxde in openbox, io genero il menu di openbox con questo comando:

openbox-xdgmenu "/etc/xdg/menus/lxde-applications.menu"

che mi da questo output:

<openbox_pipe_menu>
<menu id="xdg-menu-Accessori" label="Accessori">
<item label="Archive Manager">
<action name="Execute"><execute>file-roller   </execute></action>
</item>
<item label="Character Map">
<action name="Execute"><execute>gucharmap</execute></action>
</item>
<item label="Disks">
<action name="Execute"><execute>gnome-disks</execute></action>
</item>
<item label="Galculator">
<action name="Execute"><execute>galculator</execute></action>
</item>
<item label="Gestore file PCManFM">
<action name="Execute"><execute>pcmanfm   </execute></action>
</item>
<item label="LXTerminal">
<action name="Execute"><execute>lxterminal</execute></action>
</item>
<item label="Leafpad">
<action name="Execute"><execute>leafpad   </execute></action>
</item>
<item label="Visualizzatore di immagini">
<action name="Execute"><execute>gpicview   </execute></action>
</item>
<item label="Xfburn">
<action name="Execute"><execute>xfburn</execute></action>
</item>
<item label="Xpad">
<action name="Execute"><execute>xpad</execute></action>
</item>
</menu>
<menu id="xdg-menu-Audio e Video" label="Audio e Video">
<item label="Audacious">
<action name="Execute"><execute>audacious   </execute></action>
</item>
<item label="GNOME MPlayer">
<action name="Execute"><execute>gnome-mplayer   </execute></action>
</item>
<item label="Xfburn">
<action name="Execute"><execute>xfburn</execute></action>
</item>
<item label="guvcview">
<action name="Execute"><execute>guvcview</execute></action>
</item>
</menu>
<menu id="xdg-menu-Giochi" label="Giochi">
<item label="Penguin Canfield">
<action name="Execute"><execute>/usr/games/ace-canfield</execute></action>
</item>
<item label="Penguin Freecell">
<action name="Execute"><execute>/usr/games/ace-freecell</execute></action>
</item>
<item label="Penguin Golf">
<action name="Execute"><execute>/usr/games/ace-golf</execute></action>
</item>
<item label="Penguin Mastermind">
<action name="Execute"><execute>/usr/games/ace-mastermind</execute></action>
</item>
<item label="Penguin Merlin">
<action name="Execute"><execute>/usr/games/ace-merlin</execute></action>
</item>
<item label="Penguin Minesweeper">
<action name="Execute"><execute>/usr/games/ace-minesweeper</execute></action>
</item>
<item label="Penguin Pegged">
<action name="Execute"><execute>/usr/games/ace-pegged</execute></action>
</item>
<item label="Penguin Solitaire">
<action name="Execute"><execute>/usr/games/ace-solitaire</execute></action>
</item>
<item label="Penguin Spider">
<action name="Execute"><execute>/usr/games/ace-spider</execute></action>
</item>
<item label="Penguin Taipei">
<action name="Execute"><execute>/usr/games/ace-taipei</execute></action>
</item>
<item label="Penguin Taipei-Editor">
<action name="Execute"><execute>/usr/games/ace-taipedit</execute></action>
</item>
<item label="Penguin Thornq">
<action name="Execute"><execute>/usr/games/ace-thornq</execute></action>
</item>
</menu>
<menu id="xdg-menu-Grafica" label="Grafica">
<item label="Document Viewer">
<action name="Execute"><execute>evince   </execute></action>
</item>
<item label="Simple Scan">
<action name="Execute"><execute>simple-scan</execute></action>
</item>
<item label="mtPaint graphic editor">
<action name="Execute"><execute>mtpaint</execute></action>
</item>
</menu>
<menu id="xdg-menu-Internet" label="Internet">
<item label="Browser web Chromium">
<action name="Execute"><execute>/usr/bin/chromium-browser   </execute></action>
</item>
<item label="Pidgin Internet Messenger">
<action name="Execute"><execute>pidgin</execute></action>
</item>
<item label="Sylpheed">
<action name="Execute"><execute>sylpheed   </execute></action>
</item>
<item label="Transmission">
<action name="Execute"><execute>transmission-gtk   </execute></action>
</item>
</menu>
<menu id="xdg-menu-Strumenti di sistema" label="Strumenti di sistema">
<item label="GDebi Package Installer">
<action name="Execute"><execute>gdebi-gtk   </execute></action>
</item>
<item label="Gestione Task">
<action name="Execute"><execute>lxtask</execute></action>
</item>
<item label="IBus">
<action name="Execute"><execute>ibus-daemon --xim</execute></action>
</item>
<item label="System Profiler and Benchmark">
<action name="Execute"><execute>hardinfo</execute></action>
</item>
<item label="UXTerm">
<action name="Execute"><execute>uxterm</execute></action>
</item>
<item label="XTerm">
<action name="Execute"><execute>xterm</execute></action>
</item>
</menu>
<menu id="xdg-menu-Ufficio" label="Ufficio">
<item label="AbiWord">
<action name="Execute"><execute>abiword   </execute></action>
</item>
<item label="Document Viewer">
<action name="Execute"><execute>evince   </execute></action>
</item>
<item label="Gnumeric">
<action name="Execute"><execute>gnumeric   </execute></action>
</item>
</menu>
<separator /> 
<menu id="xdg-menu-Preferenze" label="Preferenze">
<item label="Bluetooth Manager">
<action name="Execute"><execute>blueman-manager</execute></action>
</item>
<item label="Impostazioni del monitor">
<action name="Execute"><execute>lxrandr</execute></action>
</item>
<item label="Input Method">
<action name="Execute"><execute>im-config</execute></action>
</item>
<item label="Keyboard Input Methods">
<action name="Execute"><execute>ibus-setup</execute></action>
</item>
<item label="Language Support">
<action name="Execute"><execute>/usr/bin/gnome-language-selector</execute></action>
</item>
<item label="Lubuntu Software Center">
<action name="Execute"><execute>lubuntu-software-center</execute></action>
</item>
<item label="Lxkeymap">
<action name="Execute"><execute>lxkeymap</execute></action>
</item>
<item label="Network Connections">
<action name="Execute"><execute>nm-connection-editor</execute></action>
</item>
<item label="Openbox Configuration Manager">
<action name="Execute"><execute>obconf   </execute></action>
</item>
<item label="Screensaver">
<action name="Execute"><execute>xscreensaver-demo</execute></action>
</item>
<item label="Software &amp; Updates">
<action name="Execute"><execute>software-properties-gtk</execute></action>
</item>
<item label="Software Updater">
<action name="Execute"><execute>/usr/bin/update-manager</execute></action>
</item>
<item label="Synaptic Package Manager">
<action name="Execute"><execute>synaptic-pkexec</execute></action>
</item>
<item label="Time and Date">
<action name="Execute"><execute>time-admin</execute></action>
</item>
<item label="Users and Groups">
<action name="Execute"><execute>users-admin</execute></action>
</item>
</menu>
</openbox_pipe_menu>

solo che quando metto il menu nuovo nel file menu.xml di openbox mi da l' errore root-menu not found