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/d94a52115c4975e310c3af4746bb2ec1cba54978/examples/MyAudioEffect_Float You should set ROOT_URL correctly, otherwise the web may not work correctly.