ugh

frontend/src/metabase/admin/settings/selectors.js

@@ -55,7 +55,7 @@ const SECTIONS = [
                 key: "site-locale",
                 display_name: "Language",
                 type: "select",
-                options:  MetabaseSettings.get("available_locales").map(([value, name]) => ({ name, value })),
+                options:  (MetabaseSettings.get("available_locales") || []).map(([value, name]) => ({ name, value })),
                 placeholder: "Select a language",
                 getHidden: () => MetabaseSettings.get("available_locales").length < 2
             },