Redmine

Hello,
the next problem i have is a problem with showing issue details. I get this error:

Started GET "/issues/16823" for 10.20.1.35 at 2017-07-06 13:27:43 +0200
Processing by IssuesController#show as HTML
  Parameters: {"id"=>"16823"}
  Current user: Rene.Kolbe (id=1080)
  Rendered issues/_action_menu.html.erb (46.8ms)
  Rendered issue_relations/_form.html.erb (0.0ms)
  Rendered issues/_relations.html.erb (156.3ms)
  Rendered issues/_history.html.erb (31.3ms)
  Rendered issues/_action_menu.html.erb (0.0ms)
  Rendered issues/_form.html.erb (125.0ms)
  Rendered issues/_edit.html.erb (281.3ms)
  Rendered issues/show.html.erb within layouts/base (1390.7ms)
Completed 500 Internal Server Error in 2203ms (ActiveRecord: 297.0ms)

ActionView::Template::Error (undefined method `consider_workflow?' for #<Role:0x94ae4b8>):
    1: <%= labelled_fields_for :issue, @issue do |f| %>
    2: <%= call_hook(:view_issues_form_details_top, { :issue => @issue, :form => f }) %>
    3: 
    4: <% if @issue.safe_attribute? 'is_private' %>
    5: <p style="float:right; margin-right:1em;">
    6:   <%= f.check_box :is_private, :no_label => true %><label class="inline" for="issue_is_private" id="issue_is_private_label"><%= l(:field_is_private) %></label>
    7: </p>
  app/models/issue.rb:545:in `select'
  app/models/issue.rb:545:in `workflow_rule_by_attribute'
  app/models/issue.rb:516:in `read_only_attribute_names'
  app/models/issue.rb:424:in `safe_attribute_names'
  lib/redmine/safe_attributes.rb:66:in `safe_attribute?'
  app/views/issues/_form.html.erb:4:in `block in _app_views_issues__form_html_erb__415963202_78178788'
  app/helpers/application_helper.rb:1033:in `labelled_fields_for'
  app/views/issues/_form.html.erb:1:in `_app_views_issues__form_html_erb__415963202_78178788'
  app/views/issues/_edit.html.erb:8:in `block in _app_views_issues__edit_html_erb__611879031_78462012'
  app/helpers/application_helper.rb:1026:in `labelled_form_for'
  app/views/issues/_edit.html.erb:1:in `_app_views_issues__edit_html_erb__611879031_78462012'
  app/views/issues/show.html.erb:132:in `_app_views_issues_show_html_erb___861933822_80003988'
  app/controllers/issues_controller.rb:118:in `block (2 levels) in show'
  app/controllers/issues_controller.rb:115:in `show'

What i've done? Install Redmine 3.0.4 on a new Windows Server 2012R2 and taking the existing Database of Redmine 2.3.3.

I hope anybody can help me - but i'm not a RoR Developer!

Thanks