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/b5dd5189a2209b01160886355044b4b99d7fd8a0/examples/testCompressor2 You should set ROOT_URL correctly, otherwise the web may not work correctly.