https://github.com/JRakNet/JRakNet/blob/707e9b60a69b548d521e535ab75b791f443265b9/src/main/java/com/whirvis/jraknet/Packet.java#L1112 The maximum value of type Int is 0x7FFFFF; 0xFFFFFFL is out of range. https://github.com/JRakNet/JRakNet/blob/707e9b60a69b548d521e535ab75b791f443265b9/src/main/java/com/whirvis/jraknet/Packet.java#L1160 This conditional statement always returns true; 0xFFFFFFFFFFFFFFFFFFFFFFFL represents -1.