Redmine

Hello,

my problem is the following:

I can't access the tickets with an admin account.
When i try i get this error:

"Internal error

An error occurred on the page you were trying to access.
If you continue to experience problems please contact your Redmine administrator for assistance.

If you are the Redmine administrator, check your log files for details about the error.
"

But if i try the same with a user account no error appers.

The output from my production log:

"
Started GET "/issues/48" for 192.168.10.165 at Tue Oct 23 07:45:34 +0200 2012
Processing by IssuesController#show as HTML
Parameters: {"id"=>"48"}
Completed 500 Internal Server Error in 594ms

ActiveRecord::SubclassNotFound (The single-table inheritance mechanism failed to locate $
app/models/issue_status.rb:78:in `find_new_statuses_allowed_to'
app/models/issue.rb:526:in `new_statuses_allowed_to'
app/controllers/issues_controller.rb:111:in `show'
"

Ruby version: ruby 1.8.7 (2011-06-30 patchlevel 352) [i686-linux]
rails version: Rails 3.2.3
os: ubuntu 12.04 server
mysql version: 5.5.24-0ubuntu0.12.04.1 (Ubuntu)
webrick

Thanks for any help.