This would have a good opportunity to report this using a
Support Ticket. However, lemme quote something from iRO quest wiki.
Quote:13. Go to Lyozien. Another Thugs attack happens (three of them, this time) after talking to him. After the fight, some of the of the goods will be damaged. Walk to ((airplane_01): 98, 46) to examine them. While examining them, Lyozien will reappear and hand over a white potion.
????* Note: if you fail to inspect the the damaged good, Lyozien will not reappear, and the quest will be broken for future players.
My guess is that is what happened. If you were on that step and Lyozen was working before hand, just step right up close to the box and get the propmt, and Lyozen should re-appear.