Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/AutoConnect/src/commit/3da28e351287acd28dc7f83c56501d8ddb6062d4/mkdocs/images/acelement.png
You should set ROOT_URL correctly, otherwise the web may not work correctly.