Embedding thumbnail raise errors

[gigalala]

Hi,
When i added "embed thumbnail" option to my script i got error:

thumbnail_filename = info['thumbnails'][-1]['filename'] KeyError: 'filename'

Here is my code:

        ydl_opts = {
            'key':'IgnoreErrors',
            'format': 'bestaudio/best',
            'download_archive': self.songs_data,
            'outtmpl': '/'+download_path+'/'+'%(title)s.%(ext)s',
            'progress_hooks': [self.my_hook],
            'postprocessors': [{
                'key': 'FFmpegExtractAudio',
                'preferredcodec': 'mp3',
                'preferredquality': '192'},
                {'key': 'EmbedThumbnail'},]}

Not sure if its a bug or just me doing something wrong but i tried everything

[dstftw]

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