there seems to be an error in headless-mode when accessing the system-settings (aka /dashboard?view=Shared#data page)
'./automad/src/UI/Components/Layout/SharedData.php', line 129 where Headless Class is used. but it's not yet imported in the header.
to fix this add:
BUT the system doesn't get the data anyway, i guess because a theme is needed (?) and there's no headless theme ... i don't know anything how general (Shared) data is stored in this system and how the themes are related to this. but these settings should ba stored outside of themes somehow.