SwiftEMU auth ticket wont let users on..

[zayn]

TokenID: 0Invalid Dario bug duing user login: System.NullReferenceException: Object reference not set to an instance of an object.
at Butterfly.HabboHotel.GameClients.GameClientManager.RegisterClient(GameClient client, UInt32 userID, String username) in C:\Users\Administrator\Desktop\Revision 5 - Alpha 3\Butterfly\HabboHotel\GameClients\GameClientManager.cs:line 675
at Butterfly.HabboHotel.GameClients.GameClient.tryLogin(String AuthTicket) in C:\Users\Administrator\Desktop\Revision 5 - Alpha 3\Butterfly\HabboHotel\GameClients\GameClient.cs:line 253

Please help! I have no clue.. thanks