Directory problem version 3.2

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

I bought a replacement from version 3.2. I can not run it because of the index problem.
http://ak-pil.xyz/