I keep getting the same errors, I started to remove quests, Didn't work.
I'm starting to think that If a player is lagging that'll happen.
Like if the player is on say dialup, and the command from their client will initiate without being sync'ed with the server which makes it freeze up.
So I just said the hell with it, Took the first number from that error, searched it in account and whoever made the error loses their account.
Nobody has the patience to tell everyone to not use their server if their on dialup and nobody will listen regardless so you just ban them and be happy with your satisfied users.