Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/f0c8095d93644355eccd4954db3438449e5fe64a/third-party/ArduinoJson/examples/ProgmemExample You should set ROOT_URL correctly, otherwise the web may not work correctly.