Traceback (most recent call last):
  File "/usr/share/inkscape/extensions/interp.py", line 315, in <module>
    e.affect()
  File "/usr/share/inkscape/extensions/inkex.py", line 157, in affect
    self.effect()
  File "/usr/share/inkscape/extensions/interp.py", line 127, in effect
    styles[id] = simplestyle.parseStyle(node.attributes.getNamedItem('style').value)
AttributeError: 'NoneType' object has no attribute 'value'