OK I got everything working by forcing a static IP address from my router, to prevent DHCP. You can get the mac address by inserted somewhere in the ino code :
byte mac[6];
WiFi.macAddress(mac);
Serial.print("MAC: ");
Serial.print(mac[5],HEX);
Serial.print(":");
Serial.print(mac[4],HEX);
Serial.print(":");
Serial.print(mac[3],HEX);
Serial.print(":");
Serial.print(mac[2],HEX);
Serial.print(":");
Serial.print(mac[1],HEX);
Serial.print(":");
Serial.println(mac[0],HEX);
And you will be able to read from the terminal
To solve the 'Failed to open config file' I changed one of the 'Generic ESP8266 module' options to 'Flash size : 2 M (1M SPIFFS).
Every thing works like a charm...