Crash in Redmine 2.6.10

[Alexander]

Log:

Started GET "/" for 176.192.242.97 at 2016-06-21 17:50:39 +0300
Processing by WelcomeController#index as HTML
Current user: admin (id=1)
Rendered welcome/index.html.erb within layouts/base (4.4ms)
Completed 500 Internal Server Error in 26.6ms

ActionView::Template::Error (uninitialized constant Highlightjs::Hooks::ViewHighlightedHook::UserAgent):
12: <%= stylesheet_link_tag 'rtl', :media => 'all' if l(:direction) == 'rtl' %>
13: <%= javascript_heads %>
14: <%= heads_for_theme %>
15: <%= call_hook :view_layouts_base_html_head %>
16:
17: <%= yield :header_tags -%>
18:
lib/redmine/hook.rb:61:in block (2 levels) in call_hook' lib/redmine/hook.rb:61:ineach'
lib/redmine/hook.rb:61:in block in call_hook' lib/redmine/hook.rb:58:intap'
lib/redmine/hook.rb:58:in call_hook' lib/redmine/hook.rb:158:incall_hook'
app/views/layouts/base.html.erb:15:in `_app_views_layouts_base_html_erb___2050110720569795547_34888040'