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/8ae3a159def05c6d08ae6fda3ee40bcadd828a80/docs/font-awesome
You should set ROOT_URL correctly, otherwise the web may not work correctly.
Chip Audette