Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.7/pyrenamer/pyrenamer.py", line 683, in on_preview_button_clicked
    self.file_selected_model.foreach(self.preview_rename_rows, paths)
  File "/usr/lib/pymodules/python2.7/pyrenamer/pyrenamer.py", line 548, in preview_rename_rows
    newname, newpath = renamerfilefuncs.replace_music_hachoir(name, path, newname, newpath)
  File "/usr/lib/pymodules/python2.7/pyrenamer/pyrenamer_filefuncs.py", line 552, in replace_music_hachoir
    newname = newname.replace('{artist}', '')
AttributeError: 'NoneType' object has no attribute 'replace'