Redmine

When opening Administration.Settings Internal error 500 arises. Here is the log:

Started GET "/settings" for 192.168.20.155 at 2015-02-25 09:47:29 +0200
Processing by SettingsController#index as HTML
  Current user: imc (id=3)
  Rendered settings/_general.html.erb (15.6ms)
  Rendered settings/_display.html.erb (7843.8ms)
  Rendered common/_tabs.html.erb (7984.4ms)
  Rendered settings/edit.html.erb within layouts/admin (7984.4ms)
Completed 500 Internal Server Error in 8093.8ms

ActionView::Template::Error (can not load translations from e:/data/redmine/config/locales/sl.yml: expects it to return a hash, but does not):
    3: <div class="box tabular settings">
    4: <p><%= setting_select :ui_theme, Redmine::Themes.themes.collect {|t| [t.name, t.id]}, :blank => :label_default, :label => :label_theme %></p>
    5: 
    6: <p><%= setting_select :default_language, lang_options_for_select(false) %></p>
    7: 
    8: <p><%= setting_check_box :force_default_language_for_anonymous %></p>
    9: 
  lib/redmine/i18n.rb:167:in `init_translations'
  lib/redmine/i18n.rb:181:in `lookup'
  lib/redmine/i18n.rb:98:in `block in languages_options'
  lib/redmine/i18n.rb:97:in `select'
  lib/redmine/i18n.rb:97:in `languages_options'
  lib/redmine/i18n.rb:103:in `block in languages_options'
  lib/redmine/i18n.rb:102:in `languages_options'
  app/helpers/application_helper.rb:1041:in `lang_options_for_select'
  app/views/settings/_display.html.erb:6:in `block in _app_views_settings__display_html_erb___883592265_43148952'
  app/views/settings/_display.html.erb:1:in `_app_views_settings__display_html_erb___883592265_43148952'
  app/views/common/_tabs.html.erb:22:in `block in _app_views_common__tabs_html_erb__542797332_42179844'
  app/views/common/_tabs.html.erb:21:in `each'
  app/views/common/_tabs.html.erb:21:in `_app_views_common__tabs_html_erb__542797332_42179844'
  app/helpers/application_helper.rb:328:in `render_tabs'
  app/views/settings/edit.html.erb:3:in `_app_views_settings_edit_html_erb___546118604_40738836'
  app/controllers/settings_controller.rb:28:in `index'

There is something bad with Slovenian language file sl.yml.
Affected version is 2.6.2, but older versions suffer too. After removing sl.yml, /settings page appeared normally.