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/commits/commit/c9fd115563d667dae03d68a095130596287eb5fb/android/res/drawable-hdpi/flute.png
You should set ROOT_URL correctly, otherwise the web may not work correctly.