Hi,

after migrating from 3.0.12 to 4.0, an error occurs, when I try to create a new work package with the type Bug.

This is the error log:

Started POST “/projects/giesen-intranet-v1/work_packages” for 93.211.79.226 at 2014-11-06 14:59:34 +0100
Processing by WorkPackagesController#create as HTML
Parameters: {“utf8”=>“✓”, “authenticity_token”=>“nf/mt8agv9KLIWAeb6NQkMoFqkac7QCZoxyb/gM0aDE=”, “work_package”=>{“type_id”=>“1”, “subject”=>“dsfbdfsgsgdf ”, “parent_id”=>“”, “description”=>" dfgssgfd dfg“, ”status_id“=>”1“, ”priority_id“=>”4“, ”assigned_to_id“=>”“, ”responsible_id“=>”“, ”fixed_version_id“=>”“, ”start_date“=>”“, ”due_date“=>”“, ”estimated_hours“=>”“, ”done_ratio“=>”0“, ”remaining_hours“=>”“, ”cost_object_id“=>”“}, ”attachments“=>{”1“=>{”description“=>”“}}, ”send_notification“=>”1“, ”commit“=>”Anlegen“, ”project_id“=>”kanne-intranet-v1"}
Rendered user_mailer/_issue_details.html.erb (2.7ms)
Rendered user_mailer/work_package_added.html.erb within layouts/user_mailer (8.7ms)
Rendered user_mailer/_issue_details.text.erb (1.8ms)
Rendered user_mailer/work_package_added.text.erb within layouts/user_mailer (7.6ms)

Sent mail to (2.9ms)
Redirected to https://hq.bliphead.com/work_packages/1368
Completed 302 Found in 238.7ms (ActiveRecord: 174.2ms)
Started GET “/work_packages/1368” for 93.211.79.226 at 2014-11-06 14:59:34 +0100
Processing by WorkPackagesController#show as HTML
Parameters: {“id”=>“1368”}
Rendered vendor/bundle/ruby/2.1.0/bundler/gems/openproject-costs-3eaae938ffd8/app/views/hooks/costs/_view_work_package_show_action_menu.html.erb (0.9ms)
Rendered work_packages/_action_menu.html.erb (8.4ms)
Rendered layouts/_action_menu_base.html.erb (0.1ms)
Rendered layouts/_action_menu_specific.html.erb (0.3ms)
Rendered accessibility/_empty_element_tag.html.erb (0.1ms)
Rendered work_packages/_show_attributes.html.erb (18.6ms)
Rendered work_packages/show.html.erb within layouts/base (33.9ms)
Completed 500 Internal Server Error in 63.8ms

ActionView::Template::Error (undefined method `attribute’ for nil:NilClass):
29:
30: