There are a few things you can try, first is get a dvd lens cleaner, the type with brushes, and preferably the full dvd size. The PS3 will accept micro cd's but I wouldn't risk it. Run the cleaner through, they usually have a 10 min. or so track list and eject. The try the last disc that worked in your system. If the same message occurs, a can of compressed air may do the trick, be careful though, to only spray on an angle, nozzle facing the right of your system, to prevent any more dust or debris from getting to your cpu. If this doesn't work either, your blu ray drive has become worn out and will need to be replaced. Sony will do this for a $120-150 charge, regardless if it's in warranty or not. This repair can be done by yourself, with a replacement drive, but the risk may be too great.