Hello,
It seems the latest update is broke the site. Only the preload splash page shows up.
I think it is maybe because the js.sidebar.sections.custom.links.value string is removed from locale but in the other languages is still there. FIX: display validation under custom sidebar fields (#20772) · discourse/discourse@4047073 · GitHub
Here Hivatkozás means Link.
I tried to override this string and also try safe mode or disable the custom sidebar sections but nothing worked. 
Thanks 