Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/0627ca3cb2b5be7da62e8e8865d61e6c0d1a3dba/third-party/ArduinoJson/extras/tests/MsgPackSerializer You should set ROOT_URL correctly, otherwise the web may not work correctly.