Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/OpenAudio_ArduinoLibrary/src/commit/8e1bccfca5e489883de10014d274fba09fba50e6/examples/FormantShifter_FD_OA You should set ROOT_URL correctly, otherwise the web may not work correctly.