Redmine

Hello! I'm not familiar with the language Ruby, do not themselves get fixed a problem. A problem is that occasionally an error occurs when you try to view the task tracker. And error ocurs only in the morning ... in no way manifests itself during the day.
Tell me, please, how fixed a given problem and why it occurs?
Error text from production.log:

ActionView::Template::Error (undefined method `h' for #<ViewsIssueHook:0x000000089daf28>):
    41:   <%= render :partial => 'issues/attributes' %>
    42: </div>
    43:
    44: <%= call_hook(:view_issues_form_details_bottom, { :issue => @issue, :form => f }) %>
    45: <% end %>
    46:
    47: <% heads_for_wiki_formatter %>
  lib/redmine/hook.rb:61:in `block (2 levels) in call_hook'
  lib/redmine/hook.rb:61:in `each'
  lib/redmine/hook.rb:61:in `block in call_hook'
  lib/redmine/hook.rb:58:in `tap'
  lib/redmine/hook.rb:58:in `call_hook'
  lib/redmine/hook.rb:158:in `call_hook'
  app/views/issues/_form.html.erb:44:in `block in _app_views_issues__form_html_erb__731099766081548220_72109260'
  app/helpers/application_helper.rb:1063:in `labelled_fields_for'
  app/views/issues/_form.html.erb:1:in `_app_views_issues__form_html_erb__731099766081548220_72109260'
  app/views/issues/_edit.html.erb:8:in `block in _app_views_issues__edit_html_erb__3486036772902311836_71858640'
  app/helpers/application_helper.rb:1056:in `labelled_form_for'
  app/views/issues/_edit.html.erb:1:in `_app_views_issues__edit_html_erb__3486036772902311836_71858640'
  app/views/issues/edit.html.erb:3:in `_app_views_issues_edit_html_erb___4129423346746825629_79622820'