activeadmin没有得到工作其他目前还不错…它不是ladading css文件并在admin.css文件中显示此异常

Syntax error: File to import not found or unreadable: bourbon.
              Load paths:
                /home/gull/Desktop/projects/avm_web_services/public/stylesheets/sass
                /home/gull/.rvm/gems/ruby-1.9.2-p180@rails3/gems/activeadmin-0.4.0/app/assets/stylesheets
                /home/gull/.rvm/gems/ruby-1.9.2-p180@rails3/gems/activeadmin-0.4.0/lib/active_admin/sass
        on line 11 of /home/gull/.rvm/gems/ruby-1.9.2-p180@rails3/gems/activeadmin-0.4.0/app/assets/stylesheets/active_admin/mixins/_all.css.scss
        from line 1 of /home/gull/.rvm/gems/ruby-1.9.2-p180@rails3/gems/activeadmin-0.4.0/app/assets/stylesheets/active_admin/_mixins.css.scss
        from line 2 of /home/gull/.rvm/gems/ruby-1.9.2-p180@rails3/gems/activeadmin-0.4.0/lib/active_admin/sass/active_admin.scss

提前致谢