One of two things - either the song isn't correctly formatted on the source site (it needs to be in ChordPro format), or the Chordie parser hits some sort of error and can't recover from it.
Normally it's the first one; I download the files I want to play and reformat them to the way I like them, and it also gives me the opportunity to save the files to my iPad and have them with me where ever I travel.
-[ Musician, writer, guitarist, singer ]-
My songs http://neophytte.mine.nu/audio/
My Soundcloud https://soundcloud.com/neophytte1
My YouTube https://www.youtube.com/watch?v=AHnDpTAPTUE&list=PLhpGn51pPqN6q8kmuORnuWcAXRF1_b1zV