Saving converted file under a new name fails

[Luc]

When it's done encoding and gets to giving it the correct filename, this output can be seen in the terminal:

Pipeline.play
Traceback (most recent call last):
  File "/usr/share/soundconverter/python/soundconverter/gstreamer.py", line 746, in on_task_finished
    newname = self.window.prefs.generate_filename(task.sound_file)
  File "/usr/share/soundconverter/python/soundconverter/ui.py", line 749, in generate_filename
    return generator.get_target_name(sound_file)
  File "/usr/share/soundconverter/python/soundconverter/namegenerator.py", line 94, in get_target_name
    result = pattern % d
TypeError: %d format: a number is required, not str

In the directory, temporary files are visible for each converted audio file, and playing them works fine. The encoding process worked, it just doesn't have the right file name.

In the preferences I selected "Track number - title". Filenames contained spaces, if that is any help. The parent directory contains unicode characters and a semicolon, but I didn't ask it to place it in any special directory and reading+encoding itself works just fine.

Afterwards I renamed all files with a bash one-liner, but it's clearly a bug in the program.