[Help] Connecting on same network

[BowserOne]

Hii,,
I just made my own private flyff.. everythings works just fine but .. When my sister also wants to play while I am in the game.. I get disconnected and otherwise too :O

Is this because of the same network? Or not ? XD
I will try it later today with a friend on a different network.. but still. I want an answer

Well, Tnx for your help

EDIT:
My friend came online but the same thing happened=.= really anoying....
Please help (A)

 

[BBim]

Go to accounts/characters table and change the IDs so they arent the same.