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/01cb7ba10556daffaa6d99cd155335014198618b/examples/TestFIRGeneral3 You should set ROOT_URL correctly, otherwise the web may not work correctly.