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/8e470ff2ce26eb32f7714498838b4a139ece860b/examples/FrequencyShifter_FD_OA You should set ROOT_URL correctly, otherwise the web may not work correctly.