`puppet agent -tv` command fails with error `Failed to generate external nodes for client.example.com | NoMethodError: undefined method `to_enc' for #<Nic::Base:0x007f52a2bba930>`

Issue

• puppet agent -tv command fails with below error:

# puppet agent -tv
Warning: Unable to fetch my node definition, but the agent run will continue:
Warning: Error 400 on SERVER: Failed to find client.example.com via exec: Execution of '/etc/puppet/node.rb client.example.com' returned 1:
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Failed when searching for node client.example.com: Failed to find client.example.com via exec: Execution of '/etc/puppet/node.rb client.example.com' returned 1:
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

• Production log shows the below message while puppet agent is executed:

2017-07-27 14:21:50 b91a95f2 [app] [W] Failed to generate external nodes for client.example.com  | NoMethodError: undefined method `to_enc' for #<Nic::Base:0x007f52a2bba930>  | /opt/rh/rh-ror41/root/usr/share/gems/gems/activemodel-4.1.5/lib/active_model/attribute_methods.rb:435:in `method_missing'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/activerecord-4.1.5/lib/active_record/attribute_methods.rb:208:in `method_missing'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/activerecord-4.1.5/lib/active_record/relation/delegation.rb:46:in `map'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/activerecord-4.1.5/lib/active_record/relation/delegation.rb:46:in `map'
 | /usr/share/foreman/app/models/host/managed.rb:417:in `info'
 | /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.0.0.137/app/models/katello/concerns/host_managed_extensions.rb:53:in `info_with_katello'
 | /usr/share/foreman/app/controllers/hosts_controller.rb:183:in `block in externalNodes'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/actionpack-4.1.5/lib/action_controller/metal/mime_responds.rb:433:in `call'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/actionpack-4.1.5/lib/action_controller/metal/mime_responds.rb:433:in `retrieve_collector_from_mimes'
 | /opt/rh/rh-ror41/root/usr/share/gems/gems/actionpack-4.1.5/lib/action_controller/metal/mime_responds.rb:256:in `respond_to'
 | /usr/share/foreman/app/controllers/hosts_controller.rb:181:in `externalNodes'