Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/82d9c7f770506e9eefc124af84e5d6f322e9b977/third-party/ArduinoJson/examples/JsonParserExample You should set ROOT_URL correctly, otherwise the web may not work correctly.