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/6d9f907830f2cfe1cab0f8bc580e28139ef03001/examples/TestLoader You should set ROOT_URL correctly, otherwise the web may not work correctly.