Пример

public class SerialVersionUID implements Serializable {

public SerialVersionUID() {
super();
}

public String getString(){
return field;
}

public void setString(String field){
this .field = field;
}

private String field;

}


Исправление
Объявите поле static final serialVersionUID.


public class SerialVersionUID implements Serializable {

public SerialVersionUID() {
super();
}

public String getString(){
return field;
}

public void setString(String field){
this .field = field;
}

private String field;

static final long serialVersionUID = 123;

}