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/d46ab56ed7b5bcf8028c91c45cfd310992e8163f/examples/MyAudioEffect_Float You should set ROOT_URL correctly, otherwise the web may not work correctly.