Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/esp-link/commits/commit/a9321f421ba3b786c6dd18bbe1cb7f2aaa6b44f1/espfs/mkespfsimage/Makefile You should set ROOT_URL correctly, otherwise the web may not work correctly.