Paraglider manufacturer Supair have noticed that some pilots have been unknowingly flying with broken or damaged carbon fibre seat plates, due to wear and tear, impacts, etc. Carbon fibre is very abrasive and sharp; it could injure the pilot or abrade/cut/damage the webbing and degrade the overall harness structural integrity. Therefore pilots should check their carbon fibre plates every 50 flights or every year, whichever comes first. If the plate is broken or damaged, it must be replaced!
More: Safety Information: Carbon Fiber Seat Plate Inspection