That error is that you do not have the libraries well installed or that you have the libraries of Itead and these at the same time.
I would erase the libs that you have installed from the nextion and from the arduino editor (program / include library / Add zip library) I would install everything again.
Right now, the arduino editor is not loading the libraries.
I changed the ino files somethig like that
#include <SoftwareSerial.h>
#include <Nextion.h>
SoftwareSerial nextion(10, 11);
#define nextion Serial
Nextion myNextion(nextion, 9600);
int ledStatus = 13;
void setup() {//***************************************setup***********************************************
pinMode(ledStatus, OUTPUT);
digitalWrite(ledStatus, LOW);
Serial.begin(9600);
myNextion.init(); // INICIALIZA Y VA A LA PRIMERA PAGINA
}
void loop() {
boolean botonMarcha=myNextion.getComponentValue("page1.bt0");
Serial.println(botonMarcha);
if (botonMarcha == true) digitalWrite(ledStatus, HIGH); else digitalWrite(ledStatus, LOW);
delay(1000);
}//void loop()
and in serial monitor it shows the value always 1
