Fix

src/de/steamwar/network/packets/api/BauStatusRequestPacket.java

@@ -32,5 +32,4 @@ import lombok.NoArgsConstructor;
 public class BauStatusRequestPacket extends NetworkPacket {
     private static final long serialVersionUID = 1442956004669738962L;
     private int playerId;
-    private String responseCode;
 }

src/de/steamwar/network/packets/server/api/BauStatusResponsePacket.java

@@ -34,7 +34,7 @@ import java.util.List;
 public class BauStatusResponsePacket extends NetworkPacket {
     private static final long serialVersionUID = 4338519342870271560L;
 
-    private String responseCode;
+    private int player;
     private boolean serverStatus;
     private List<Integer> onlinePlayers;
 }