Players who haven't joined your server since the UUID conversion will have a null name. As a result, if you try to /openinv a player who has joined your server since then, the loop can break due to a NPE while checking other players. This null check should fix that problem.
Players who haven't joined your server since the UUID conversion will have a null name. As a result, if you try to /openinv a player who has joined your server since then, the loop can break due to a NPE while checking other players. This null check should fix that problem.