openproject/app/views/common/_error_base.html.erb

<%#-- copyright
OpenProject is a project management system.
Copyright (C) 2012-2015 the OpenProject Foundation (OPF)

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License version 3.

OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
Copyright (C) 2006-2013 Jean-Philippe Lang
Copyright (C) 2010-2013 the ChiliProject Team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

See doc/COPYRIGHT.rdoc for more details.

++#%>

<div class="errorExplanation" id="errorExplanation" role="alert">
  <% if content_for?(:error_details) %>
    <h2><%= error_message %></h2>
    <%= content_for :error_details %>
  <% else %>
    <%= error_message %>
  <% end %>
  <i class="icon-close close-handler" role="button" tabindex="0" aria-label="{{ ::I18n.t('js.close_popup_title') }}"></i>
</div>