zero length field name in format

Dec-05 14:05:41 DEBUG    CP Server Thread-2 :: 79349: Downloading subtitles for episode 6x7
Dec-05 14:05:41 DEBUG    Setting languages to [u'fr']
Dec-05 14:05:41 DEBUG    Setting plugins to ['OpenSubtitles', 'TheSubDB', 'SubsWiki']
Dec-05 14:05:41 DEBUG    Worker Thread-13 added to the pool
Dec-05 14:05:41 DEBUG    Listing subtitles set([u'fr']) for u'/volume1/Video/SERIES/Dexter/Dexter.S06E07.720p.HDTV.X264-DIMENSION.mkv' with ['OpenSubtitles', 'TheSubDB', 'SubsWiki']
Dec-05 14:05:42 DEBUG    Initializing
Dec-05 14:05:43 DEBUG    Getting subtitles [{'moviebytesize': '1734318968', 'sublanguageid': 'fre', 'moviehash': '2d536e1add064ae3'}] with token g1qtpj1rikr8dgmferfs9ebm47
Dec-05 14:05:43 DEBUG    Initializing
Dec-05 14:05:44 DEBUG    Could not find subtitles for hash 658c92177f4620fa37b8073a10c2076c with languages set([u'fr']) (only set(['en', 'pt']) available)
Dec-05 14:05:44 DEBUG    Initializing
Dec-05 14:05:44 DEBUG    Getting subtitles for Dexter season 6 episode 7 with languages set([u'fr'])
Dec-05 14:05:45 DEBUG    None of subtitle keywords set([u'lol']) in set(['h264', 'hdtv', '720p'])
Dec-05 14:05:45 DEBUG    CP Server Thread-2 :: Error occurred when downloading subtitles: zero length field name in format
Dec-05 14:05:45 DEBUG    Poison pill received in thread Thread-13
Dec-05 14:05:45 DEBUG    Terminating
Dec-05 14:05:45 DEBUG    Terminating
Dec-05 14:05:45 DEBUG    Terminating
Dec-05 14:05:45 DEBUG    Thread Thread-13 terminated