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/686fceb41c9fb5a28ae61a192e41e04aa5e091c2/examples/FormantShifter_FD_OA You should set ROOT_URL correctly, otherwise the web may not work correctly.