after add a diagram, dashboard never open and show error 500

[cleocir]

after add a diagram file, dashboard never show.

in production.log a look these errors:

ActionView::TemplateError (private method `gsub' called for nil:NilClass) on line #40 of vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:
37: <%= user_story.description -%>^M
38: ^M
39: ^M
40: ^M
41: ^M
42: ^M
43:

^M

vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:40
vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:39
vendor/plugins/redmine_sprints/app/views/sprints/show.html.erb:66
vendor/plugins/redmine_sprints/app/views/sprints/show.html.erb:65
vendor/plugins/redmine_sprints/app/controllers/sprints_controller.rb:37:in `show'
/usr/lib/ruby/1.8/rack/adapter/rails.rb:75:in `call'
/usr/lib/ruby/1.8/thin/connection.rb:76:in `pre_process'
/usr/lib/ruby/1.8/thin/connection.rb:74:in `catch'
/usr/lib/ruby/1.8/thin/connection.rb:74:in `pre_process'
/usr/lib/ruby/1.8/eventmachine.rb:1064:in `call'
/usr/lib/ruby/1.8/eventmachine.rb:1064:in `spawn_threadpool'
/usr/lib/ruby/1.8/eventmachine.rb:1061:in `initialize'
/usr/lib/ruby/1.8/eventmachine.rb:1061:in `new'
/usr/lib/ruby/1.8/eventmachine.rb:1061:in `spawn_threadpool'
/usr/lib/ruby/1.8/eventmachine.rb:1053:in `defer'
/usr/lib/ruby/1.8/thin/connection.rb:54:in `process'
/usr/lib/ruby/1.8/thin/connection.rb:42:in `receive_data'
/usr/lib/ruby/1.8/eventmachine.rb:240:in `run_machine'
/usr/lib/ruby/1.8/eventmachine.rb:240:in `run'
/usr/lib/ruby/1.8/thin/backends/base.rb:57:in `start'
/usr/lib/ruby/1.8/thin/server.rb:156:in `start'
/usr/lib/ruby/1.8/thin/controllers/controller.rb:80:in `start'
/usr/lib/ruby/1.8/thin/runner.rb:174:in `send'
/usr/lib/ruby/1.8/thin/runner.rb:174:in `run_command'
/usr/lib/ruby/1.8/thin/runner.rb:140:in `run!'
/usr/bin/thin:6

Rendering /home/rails/redmine-1.1.3/public/500.html (500 Error)
rendering section "request"
rendering section "session"
rendering section "environment"
rendering section "backtrace"

[cleocir]

redmine version 1.1.3

[pskk]

I have the same problem, someone can help me please?

ActionView::TemplateError (private method `gsub' called for nil:NilClass) on line #40 of vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:
37: <% user_story.description %>
38:
39:
40:
41:
42:
43:

vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:40
vendor/plugins/redmine_sprints/app/views/user_stories/_us_for_show.html.erb:39
vendor/plugins/redmine_sprints/app/views/sprints/show.html.erb:66
vendor/plugins/redmine_sprints/app/views/sprints/show.html.erb:65
vendor/plugins/redmine_sprints/app/controllers/sprints_controller.rb:38:in `show'
config/initializers/mongrel.rb:62:in `dispatch_cgi'