You may try flac frontend and test for errors. You can set test/decode through errors. Some folks just test a new well working beta version of it here http://www.hydrogenaudio.org/forums/index....c=99803&hl=Maybe you are able to decode the file to wav and go further from there. You should listen at 21:36 if you hear a glitch that hints to a corrupt file.
Does it decode completely? The error itself tells you the file is broken, no idea how to fix it. Only chance is to decodce through errors and hope it is only some small parts missing.