I'm not able to create a new host group:

Oops, we're sorry but something went wrong

x undefined local variable or method `freeip_subnets_path' for #<#<Class:0x007fe5b91c34e0>:0x007fe5b8d20e60>
If you feel this is an error with Foreman itself, please open a new issue with Foreman ticketing system, You would probably need to attach the Full trace and relevant log entries.

NameError
undefined local variable or method `freeip_subnets_path' for #<#<Class:0x007fe5b91c34e0>:0x007fe5b8d20e60>
app/views/common/_domain.html.erb:4:in `block in app_views_common_domain_html_erb__1242807342534462145_70312311419900'
app/views/common/_domain.html.erb:1:in `_app_views_common__domain_html_erb__1242807342534462145_70312311419900'
app/views/common/_domain_subnet.html.erb:7:in `block in app_views_common_domain_subnet_html_erb___4555965924254477768_70312312217860'
app/views/common/_domain_subnet.html.erb:1:in `_app_views_common__domain_subnet_html_erb___4555965924254477768_70312312217860'
app/views/hostgroups/_form.html.erb:43:in `block in app_views_hostgroups_form_html_erb__4008013229379639853_70312312494800'
app/helpers/layout_helper.rb:211:in `form_for'
app/views/hostgroups/_form.html.erb:2:in `_app_views_hostgroups__form_html_erb__4008013229379639853_70312312494800'
app/views/hostgroups/new.html.erb:3:in `_app_views_hostgroups_new_html_erb__130460783755124437_70312312503660'
lib/foreman/thread_session.rb:31:in `clear_thread'

Foreman Version 1.2.0