Как помочь redmine выбрать версию?

Question

[Николай Шкрылев]

При установке плагина https://github.com/swiehr/redmine_customize выдал много текста

Bundler could not find compatible versions for gem "nokogiri":
  In Gemfile:
    nokogiri (>= 1.6.7.2)

    deface (< 1.0.0) was resolved to 0.5.2, which depends on
      nokogiri (~> 1.4.3)

    rails-html-sanitizer (>= 1.0.3) was resolved to 1.0.3, which depends on
      loofah (~> 2.0) was resolved to 2.0.3, which depends on
        nokogiri (>= 1.5.9)

    rails (~> 4.2.5) was resolved to 4.2.5, which depends on
      railties (= 4.2.5) was resolved to 4.2.5, which depends on
        actionpack (= 4.2.5) was resolved to 4.2.5, which depends on
          rails-dom-testing (>= 1.0.5, ~> 1.0) was resolved to 1.0.7, which depends on
            nokogiri (~> 1.6.0)
Bundler could not find compatible versions for gem "rails":
  In Gemfile:
    rails (~> 4.2.5)

    deface (< 1.0.0) was resolved to 0.1.0, which depends on
      rails (~> 3.0.0)

    render_parent (>= 0.0.4) was resolved to 0.0.8, which depends on
      rails (>= 2.3.0)

Что есть:
Ubuntu 16
Redmine

redmine/xenial,xenial,now 3.2.1-2 all [установлен]
redmine-pgsql/xenial,xenial,now 3.2.1-2 all [установлен]
ruby/xenial,xenial,now 1:2.3.0+1 all [установлен, автоматически]
...

root@redmine:~# gem search -l ruby

*** LOCAL GEMS ***

concurrent-ruby (1.0.2)
ruby-hmac (0.4.0)
ruby-openid (2.7.0)
root@redmine:~# gem search -l rails

*** LOCAL GEMS ***

coffee-rails (4.1.0)
jquery-rails (4.0.5)
rails (4.2.6)
rails-deprecated_sanitizer (1.0.3)
rails-dom-testing (1.0.6)
rails-html-sanitizer (1.0.3)
rails-observers (0.1.2)
roadie-rails (1.1.0)
sass-rails (5.0.4)
sprockets-rails (2.3.2)

Redmine плагины

• Image Clipboard Paste - 1.0.0
  
• Redmine Issue Checklist Plugin - 2.0.8
  
• Redmine Lightbox 2 - 0.2.7
  

Gem list pastebin.com/NBGx57V2
Установленные пакеты ubuntu pastebin.com/qpYR0gzW

Подскажите, плз, что можно сделать. Я не рубист от слова совсем.