Redmine

After upgrading to 2.6.1.stable.13876 (from svn) from 2.4.5 I started getting errors similar to this:

    Processing by*  ProjectsController#settings as HTML
      Parameters: {"id"=>"alberdi-sgo-del-estero"}
      Current user: lrame (id=4)
      Rendered projects/_form.html.erb (247.5ms)
      Rendered projects/_edit.html.erb (252.8ms)
      Rendered projects/settings/_modules.html.erb (7.7ms)
      Rendered projects/settings/_members.html.erb (110.3ms)
      Rendered projects/settings/_versions.html.erb (7.1ms)
      Rendered common/_tabs.html.erb (388.7ms)
      Rendered projects/settings.html.erb within layouts/base (389.8ms)
    Completed 500 Internal Server Error in 415.1ms

    ActionView::Template::Error (undefined method `name' for nil:NilClass):
        33: <% end %>
        34:
        35: <div class="contextual">
        36: <% if @project.versions.any? %>
        37:   <%= link_to l(:label_close_versions), close_completed_project_versions_path(@project), :method => :put %>
        38: <% end %>
        39: </div>
      app/views/projects/settings/_versions.html.erb:36:in `_app_views_projects_settings__versions_html_erb__4284803287680039117_69974521564700'
      app/views/common/_tabs.html.erb:22:in `block in _app_views_common__tabs_html_erb__3923104128307704039_31947360'
      app/views/common/_tabs.html.erb:21:in `each'
      app/views/common/_tabs.html.erb:21:in `_app_views_common__tabs_html_erb__3923104128307704039_31947360'
      app/helpers/application_helper.rb:328:in `render_tabs'
      app/views/projects/settings.html.erb:3:in `_app_views_projects_settings_html_erb__2442961766712979311_32041660'

This install is running on Ubuntu 12.04 with Ruby 2.0.0 and mysql2 adapter.

What can be happening? how can I fix it?.