Empty serial monitor

This code seemed to work fine before but after changing the wifi it suddenly doesn’t do anything anymore. When looking at the serial monitor there seems to be no data flow. When using another code to read out the sensor data it shows that the sensor and wemos work fine. So why can’t I get information using this code?

#define BLYNK_PRINT Serial

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "xxxxx";
char ssid[] = "xxxxx";
char pass[] = "xxxxx";

int fsrPin = 0;
int fsrReading;

void setup(void) {
  Serial.begin(9600); 
  Blynk.begin(auth, ssid, pass);  
  pinMode(LED_BUILTIN, OUTPUT);
}

BLYNK_READ(V5)
{
  fsrReading = analogRead(fsrPin);
  Blynk.virtualWrite(V5, fsrReading);
}

void loop(void) {
  Serial.print("Analog reading = ");
  Serial.print(fsrReading);
    if (fsrReading > 700) {
       digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
    }
    else {
       digitalWrite(LED_BUILTIN, LOW);
    }
  Blynk.run();
}

So why can't I get information using this code?

Because you may not be getting into loop(). Add Serial.print() statements to setup(), after each line of code, to find out where you get to, and where you don't get to.

...and put a Serial.flush () after each print, as a precaution.