When install the foerman plugin(ruby193-rubygem-foreman-mco-0.0.1-3) ,it will occour error

hi,
My Environment:
[root@foreman foreman_mco]# rpm -qa foreman
foreman-1.4.2-1.el6.noarch
[root@foreman foreman_mco]# rpm -qa ruby193-rubygem-foreman-mco
ruby193-rubygem-foreman-mco-0.0.1-3.el6.noarch

··· ----------------------

After I finished the installation of foreman-mco plugin , I could see the
plugin of mco in settings ,and could set value=true
But ,when I click the Hosts-All hosts , errors will occour .Just as follows:

Oops, we’re sorry but something went wrong

Warning!cannot load such file – uglifier (in
/opt/rh/ruby193/root/usr/share/gems/gems/foreman-mco-0.0.1/app/assets/javascripts/foreman_mco/mco_hosts_extensions.js)

If you feel this is an error with Foreman itself, please open a new issue
with Foreman ticketing system
http://theforeman.org/projects/foreman/issues, You would probably need to
attach the Full trace https://192.168.13.100/hosts# and relevant log
entries.

Back https://192.168.13.100/