Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/music-synthesizer-for-android/src/commit/4e55f13f2bdc2e0f609a5df83edb00a9607a021c/android/res/drawable-hdpi/voice.png
You should set ROOT_URL correctly, otherwise the web may not work correctly.