Cannot save settings

[Pankraty]

I was able to install the plugin and to open the configuration page but every time I try to save my changes I get the server error.

The log messages are these:

Started POST "/settings/plugin/silent_statuses" for %HIDDEN% at 2018-07-06 00:39:47 +0400
Processing by SettingsController#plugin as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"%HIDDEN%", "settings"=>[""], "commit"=>"Применить", "id"=>"silent_statuses"}
  Current user: alex (id=1)
Completed 500 Internal Server Error in 25ms (ActiveRecord: 3.2ms)

NoMethodError (undefined method `permit!' for [""]:Array
Did you mean?  permutation):
  app/controllers/settings_controller.rb:70:in `plugin'
  lib/redmine/sudo_mode.rb:63:in `sudo_mode'

Environment:
Redmine version 3.4.1.stable
Ruby version 2.3.4-p301 (2017-03-30) [x86_64-linux]
Rails version 4.2.8