It does not consume a ticket. If you had 25 tickets, used one, got a 30% overall int, then tried to use it again and got the error the 2nd time, then you will naturally open your cash inventory to check. The problem here is that at this time your inventory still shows 25 tickets, meaning the server has not caught up and consumed the last ticket you used. This is why you are getting an error. Naturally, after a few seconds you see your ticket count go down from 25 to 24. This leads people to believe the error takes your tickets. The error actually does not consume your ticket. Rather the opposite. The sever finally catches up and finally deducts 1 ticket (the one you used to get the 30% overall int in this example). To put it very simply, sometimes it takes the server around 5 seconds to remove a ticket from your inventory when you use one due to lag. The error should really just say "Please wait, the server is still processing your last ticket."