A) Use the standard Hobie halyard system
B) Check the track for cracks
The track may be split, but the key is actually in the halyard hook system. If you bypass the halyard hook system and use a rope halyard that does not have the wire and swedge to lock in the hook up top... the sail will not be properly held in at the head. The leech loads will pull to heavily on the plastic luff track and the head can pull out as described.
The track replacement part is #38584001
Instructions are here: http://www.hobiecat.com/support/pdfs/38584001.pdf