Redmine

Dear,
I am getting error 500 when try make a search.
Below the production log

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Started GET "/search?utf8=%E2%9C%93&q=asdfas" for xxx.xxx.xxx.xxx at 2015-12-01 22:54:04 -0500
Processing by SearchController#index as HTML
Parameters: {"utf8"=>"✓", "q"=>"asdfas"}
[1m[36m (0.3ms)[0m [1mSELECT MAX FROM `settings`[0m
[1m[35mUser Load (0.2ms)[0m SELECT `users`.* FROM `users` WHERE `users`.`type` IN ('User', 'AnonymousUser') AND `users`.`status` = 1 AND `users`.`id` = 1 LIMIT 1
Current user: mauro (id=1)
Completed 500 Internal Server Error in 20ms (ActiveRecord: 0.5ms)

ArgumentError (wrong number of arguments (1 for 0)):
lib/plugins/acts_as_searchable/lib/acts_as_searchable.rb:194:in `call'
lib/plugins/acts_as_searchable/lib/acts_as_searchable.rb:194:in `search_scope'
lib/plugins/acts_as_searchable/lib/acts_as_searchable.rb:92:in `search_result_ranks_and_ids'
lib/redmine/search.rb:127:in `block in load_result_ids'
lib/redmine/search.rb:125:in `each'
lib/redmine/search.rb:125:in `load_result_ids'
lib/redmine/search.rb:115:in `block in load_result_ids_from_cache'
lib/redmine/search.rb:114:in `load_result_ids_from_cache'
lib/redmine/search.rb:99:in `result_ids'
lib/redmine/search.rb:70:in `result_count'
app/controllers/search_controller.rb:65:in `index'
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My configuration
Redmine version 3.0.3.stable.14369
Ruby version 2.0.0-p643 (2015-02-25) [x86_64-linux]
Rails version 4.2.2
Environment production
Database adapter Mysql2

Thanks for help
Mauro