Anguish/Ascend cannon help

can anyone help me with this the cannon sets up fine but when i try to make it fire it kicks me out of the game and i get this



java.lang.ArrayIndexOutOfBoundsException: 63
Error: T2 - 101,85,65 - 2,2675,3714 - 2,0,
at com.client.Client.method137(Client.java:15348)
at com.client.Client.parsePacket(Client.java:17045)
at com.client.Client.mainGameProcessor(Client.java:40 52)
at com.client.Client.processGameLoop(Client.java:3337 )
at com.client.RSApplet.run(RSApplet.java:275)
at com.client.Client.run(Client.java:6282)
at java.lang.Thread.run(Unknown Source)