Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/29d8634a1e15e31224583b069132cb11c430ec68/third-party/ArduinoJson/extras/tests/IntegrationTests You should set ROOT_URL correctly, otherwise the web may not work correctly.