Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/db2d608cd02ff6c460372b8a6c0c88832a31a247/third-party/ArduinoJson/examples/JsonGeneratorExample You should set ROOT_URL correctly, otherwise the web may not work correctly.