Redmine

Hello,

after upgrading from 2.6.1 to 3.0.3 search function doesn't work.
On the web screen I have the 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."

In the apache2 log I have:
"App 19004 stderr: NoMethodError (undefined method `search_results_per_page' for #<Class:0x000000044f0fe8>):
App 19004 stderr: app/controllers/search_controller.rb:69:in `index' "

I use admin user having the necessary permissions.

My components:

OS: Ubuntu 12.04.5 LTS
Apache 2.2.22

Environment:
Redmine version 3.0.3.stable
Ruby version 1.9.3-p545 (2014-02-24) [x86_64-linux]
Rails version 4.2.1
Environment production
Database adapter Mysql2
SCM:
Git 1.7.9.5
Filesystem
Redmine plugins:
redmine_contacts 4.0.1
redmine_contacts_invoices 4.0.0