Redmine

ruby 1.9.3p448
Rails 3.2.13
redmine 2.3.3
SCM ：subversion
URL ：svn://x.x.x.x/ （ user TortoiseSVN is OK!）
But user repository error 500,help me please!
Intergel ERROR 500
ActionView::Template::Error (undefined method `-' for {:length=>50}:Hash):
25: <td class="revision"><%= link_to_revision(entry.changeset, Jack Zheng) if entry.changeset ></td>
26: <td class="age"><= distance_of_time_in_words(entry.lastrev.time, Time.now) if entry.lastrev && entry.lastrev.time ></td>
27: <td class="author"><= entry.author ></td>
28: <td class="comments"><=h truncate(entry.changeset.comments, :length => 50) if entry.changeset ></td>
29: < end >
30: </tr>
31: < end %>
config/environment.rb:22:in `truncate'
app/views/repositories/_dir_list_content.html.erb:28:in `block in app_views_repositories_dir_list_content_html_erb__4244999199527241588_58948520'
app/views/repositories/_dir_list_content.html.erb:1:in `each'
app/views/repositories/_dir_list_content.html.erb:1:in `_app_views_repositories__dir_list_content_html_erb__4244999199527241588_58948520'
app/views/repositories/_dir_list.html.erb:16:in `_app_views_repositories__dir_list_html_erb__780208683014920164_58915120'
app/views/repositories/show.html.erb:11:in `_app_views_repositories_show_html_erb__3973464992110231650_58544200'
app/controllers/repositories_controller.rb:125:in `show'