Ruby on rails 如果发生冲突，则提出：无法激活rails dom测试

我第一次安装RubyonRails。当我试图运行服务器时，发生了以下错误。我找了很多，但找不到解决办法。我已卸载了在Windows上不工作的nokogiri 1.6.6。之后，我安装了

1.8.+

version。现在我面临着这个错误

C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:2112:in raise_if_conflicts: Unable to activate rails-dom-testing-2.0.1, because nokogiri-1.8.0-x86-mingw32 conflicts with nokogiri (~> 1.6.0) (Gem::ConflictError)
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1280:in activate
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1314:in block in activate_dependencies
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in each
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in activate_dependencies
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1282:in activate
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1314:in block in activate_dependencies
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in each
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in activate_dependencies
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1282:in activate
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core_ext/kernel_gem.rb:67:in block in gem
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core_ext/kernel_gem.rb:66:in synchronize
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core_ext/kernel_gem.rb:66:in gem
        from C:/RailsInstaller/Ruby2.2.0/bin/rails:22:in <main>

C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:2112:in raise\u if\u冲突：无法激活rails-dom-testing-2.0.1，因为nokogiri-1.8.0-x86-mingw32与nokogiri冲突（~>1.6.0）（Gem:：ConflictError）
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1280:in-activate
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1314:in块中的activate\u依赖项
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:每个
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in-activate\u-dependencies
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1282:in-activate
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1314:in块中的activate\u依赖项
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:每个
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1300:in-activate\u-dependencies
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/specification.rb:1282:in-activate
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core\u ext/kernel\u gem.rb:67:gem中的块
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core\u ext/kernel\u gem.rb:66:in synchronize
来自C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/rubygems/core\u ext/kernel\u gem.rb:66:in gem
从C:/RailsInstaller/Ruby2.2.0/bin/rails:22:in