Back-ported in https://github.com/ManageIQ/manageiq/pull/10230

Verified in 5.6.2.

irb(main):007:0> $evm.vmdb(:Lan).all.first.taggable?
=> false
irb(main):008:0> $evm.vmdb(:Lan).all.first.tags
MiqAeException::UntaggableModel: Model MiqAeMethodService::MiqAeServiceLan doesn't support tagging
	from /var/www/miq/vmdb/lib/miq_automation_engine/engine/miq_ae_service_model_base.rb:268:in `verify_taggable_model'
	from /var/www/miq/vmdb/lib/miq_automation_engine/engine/miq_ae_service_model_base.rb:238:in `tags'
	from (irb):7
	from /opt/rh/cfme-gemset/gems/railties-5.0.0.1/lib/rails/commands/console.rb:65:in `start'
	from /opt/rh/cfme-gemset/gems/railties-5.0.0.1/lib/rails/commands/console_helper.rb:9:in `start'
	from /opt/rh/cfme-gemset/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:78:in `console'
	from /opt/rh/cfme-gemset/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
	from /opt/rh/cfme-gemset/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
	from bin/rails:4:in `require'
	from bin/rails:4:in `<main>'

Works as expected.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2016-1996.html