Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/uClock/src/commit/ec19c8d6340d27ff692e9d2e9c3ce3fd686772bc/examples/TeensyUsbSlaveMidiClockMonitor
You should set ROOT_URL correctly, otherwise the web may not work correctly.
midilab