Can't open the app: Error on line 1 char 1 (MenuEditor.py)

Hi, I'm running Ubuntu 17.10 64bit (Gnome 3.26.2)
Just can't open the app... and I need some help here

This is the error when I try to run the app on terminal:

USER:~$ menulibre
/usr/lib/python3/dist-packages/menulibre/MenuEditor.py:28: PyGIWarning: GMenu was imported without specifying a version first. Use gi.require_version('GMenu', '3.0') before import to ensure that the right version gets loaded.
  from gi.repository import GdkPixbuf, Gio, GLib, GMenu, Gtk
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/menulibre/MenulibreApplication.py", line 1717, in do_activate
    self.win = MenulibreWindow(self)
  File "/usr/lib/python3/dist-packages/menulibre/MenulibreApplication.py", line 207, in __init__
    self.configure_application_treeview(builder)
  File "/usr/lib/python3/dist-packages/menulibre/MenulibreApplication.py", line 462, in configure_application_treeview
    self.treeview = MenulibreTreeview.Treeview(self, builder)
  File "/usr/lib/python3/dist-packages/menulibre/MenulibreTreeview.py", line 43, in __init__
    self._configure_treeview(builder)
  File "/usr/lib/python3/dist-packages/menulibre/MenulibreTreeview.py", line 54, in _configure_treeview
    treestore = MenuEditor.get_treestore()
  File "/usr/lib/python3/dist-packages/menulibre/MenuEditor.py", line 113, in get_treestore
    menu = get_menus()[0]
  File "/usr/lib/python3/dist-packages/menulibre/MenuEditor.py", line 175, in get_menus
    menu = MenuEditor()
  File "/usr/lib/python3/dist-packages/menulibre/MenuEditor.py", line 227, in __init__
    self.load()
  File "/usr/lib/python3/dist-packages/menulibre/MenuEditor.py", line 245, in load
    if not self.tree.load_sync():
GLib.Error: g-markup-error-quark: Error on line 1 char 1: Document was empty or contained only whitespace (1)