Hi Maplers, We have discovered an issue with the "Intense Power Crystal" you receive from bosses. The "Intense Power Crystal" meso value is lost when your character has been logged off for a period of time and the item cannot be sold. However, the "Intense Power Crystal" can still be dropped and will expire correctly. Please make sure to exchange this item with "Collector" in the Free Market before you log off your character to ensure you get your meso reward. This will be corrected in the next maintenance. We apologize for the inconvenience. Sincerely, MapleStory Team View on the Official Site