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/a23e900831eb9293705c7405154eef8042c46d9c/examples/FineFreqShift_OA
You should set ROOT_URL correctly, otherwise the web may not work correctly.