fixed bugs, memory leaks, etc

src/main/java/dev/zprestige/prestige/network/PacketSender.java

@@ -5,6 +5,8 @@ import net.minecraft.network.packet.Packet;
 
 public class PacketSender implements MinecraftAccess {
     public static void sendPacket(Packet packet) {
-        mc.getNetworkHandler().sendPacket(packet);
+        if (mc.getNetworkHandler() != null) {
+            mc.getNetworkHandler().sendPacket(packet);
+        }
     }
 }