Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/c631d60eea351a1d4654012056a7816f907f76c6/third-party/ArduinoJson/extras/tests/JsonArray You should set ROOT_URL correctly, otherwise the web may not work correctly.