Comment 4 for bug 1325420

"Open" and "Open in Terminal" does not work in the Directory Menu panel plugin with the Lubuntu panel session, but it does with the default session. If comparing the session configuration files ~/.config/lxpanel/Lubuntu/config and ~/.config/lxpanel/default/config it seems like there is an issue with the lxsession-default filemanager|terminal command used to register the appropiate default applications for the panel. The straight commands for FileManager and Terminal still work as expected.

As a workaround you can change these entries in the configuration file for the panel to what is originally used for the default panel session:

1. Open ~/.config/lxpanel/Lubuntu/config in a text editor.

2. Change the entries for FileManager and Terminal:

[Command]
FileManager= pcmanfm %s
Terminal=lxterminal
Logout=lxsession-default quit

3. Save file and restart panel:$ lxpanelctl restart

Directory Menu plugin will work again. Of course, you could also change the entries to commands for a different file manager or terminal application.