In this sketch (which i named ESP32_Client_1_LED_DS18B20) I am sure I have the libraries:

#include <WiFi.h>
extern “C” {
#include “freertos/FreeRTOS.h”
#include “freertos/timers.h”
}
#include <AsyncMqttClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>

correct – I have reinstalled them from zip files I downloaded today.

I am also sure that I have the correct board manager URL’s installed

When I test or try to complie the sketch, I get the following errors:

ESP32_Client_1_LED_DS18B20:53:16: error: variable or field ‘WiFiEvent’ declared void
void WiFiEvent(WiFiEvent_t event) {
^
ESP32_Client_1_LED_DS18B20:53:16: error: ‘WiFiEvent_t’ was not declared in this scope
E:\00000 -E-Data\Arduino\ESP32_Client_1_LED_DS18B20\ESP32_Client_1_LED_DS18B20.ino: In function ‘void connectToWifi()’:
E:\00000 -E-Data\Arduino\ESP32_Client_1_LED_DS18B20\ESP32_Client_1_LED_DS18B20.ino:45:38: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings]
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
^
E:\00000 -E-Data\Arduino\ESP32_Client_1_LED_DS18B20\ESP32_Client_1_LED_DS18B20.ino: At global scope:
ESP32_Client_1_LED_DS18B20:53:16: error: variable or field ‘WiFiEvent’ declared void
void WiFiEvent(WiFiEvent_t event) {
^
ESP32_Client_1_LED_DS18B20:53:16: error: ‘WiFiEvent_t’ was not declared in this scope
exit status 1
variable or field ‘WiFiEvent’ declared void

Please let me know what I am doing wrong.

As always, many thanks,

Steve