FIX: Show an error page if finish-installation can't run

app/controllers/finish_installation_controller.rb

@@ -59,6 +59,7 @@ class FinishInstallationController < ApplicationController
     end
 
     def ensure_no_admins
+      preload_anonymous_data
       raise Discourse::InvalidAccess.new unless SiteSetting.has_login_hint?
     end
 end