@mfalkvidd Thanks, that solution worked and sorry I should have found that posting myself of course. FYI, for loading the ESP8266 Board definitions the usual URL https://arduino.esp8266.com/stable/package_esp8266com_index.json did not work for me anymore. Instead I had to use https://github.com/esp8266/Arduino/releases/download/2.4.2/package_esp8266com_index.json