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/a8a82af2a5c305f511510fe802ed9b744ba8a9ce/examples/FormantShifter_FD_OA You should set ROOT_URL correctly, otherwise the web may not work correctly.