Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/MicroDexed/src/commit/6993cdcb0b69456e6d69af6afcbb9397ca0f5d67/doc/manuals/MicroDexed-User_Manual/images/10_MIDISendVoice_3.jpg
You should set ROOT_URL correctly, otherwise the web may not work correctly.