Description of problem:
----------------------
The UI blows up with this error while clicking on Orchestration Stack parameters.

Error text:
undefined method `split' for nil:NilClass [orchestration_stack/parameters]

Snippet from production.log:

[----] I, [2016-10-12T17:19:57.734394 #11810:1686edc]  INFO -- : Started GET "/orchestration_stack/parameters/20" for 127.0.0.1 at 2016-10-12 17:19:57 -0400
[----] I, [2016-10-12T17:19:57.736890 #11810:1686edc]  INFO -- : Processing by OrchestrationStackController#parameters as HTML
[----] I, [2016-10-12T17:19:57.737016 #11810:1686edc]  INFO -- :   Parameters: {"id"=>"20"}
[----] F, [2016-10-12T17:19:57.765225 #11810:1686edc] FATAL -- : Error caught: [NoMethodError] undefined method `split' for nil:NilClass
/var/www/miq/vmdb/app/models/miq_report/search.rb:15:in `association_column'
/var/www/miq/vmdb/app/models/miq_report/search.rb:47:in `block in get_order_info'
/var/www/miq/vmdb/app/models/miq_report/search.rb:46:in `collect'
/var/www/miq/vmdb/app/models/miq_report/search.rb:46:in `get_order_info'
/var/www/miq/vmdb/app/models/miq_report/search.rb:92:in `paged_view_search'
/var/www/miq/vmdb/app/controllers/application_controller.rb:1602:in `get_view'
/var/www/miq/vmdb/app/controllers/application_controller/ci_processing.rb:1047:in `show_details'
/var/www/miq/vmdb/app/controllers/application_controller/ci_processing.rb:2813:in `show_association'
/var/www/miq/vmdb/app/controllers/orchestration_stack_controller.rb:81:in `parameters'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/basic_implicit_render.rb:4:in `send_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/abstract_controller/base.rb:188:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/rendering.rb:30:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/abstract_controller/callbacks.rb:20:in `block in process_action'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:126:in `call'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:506:in `block (2 levels) in compile'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:455:in `call'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:101:in `__run_callbacks__'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_process_action_callbacks'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:90:in `run_callbacks'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/abstract_controller/callbacks.rb:19:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/rescue.rb:20:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/notifications.rb:164:in `block in instrument'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/notifications/instrumenter.rb:21:in `instrument'
/opt/rh/cfme-gemset/gems/activesupport-5.0.0.1/lib/active_support/notifications.rb:164:in `instrument'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal/params_wrapper.rb:248:in `process_action'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/railties/controller_runtime.rb:18:in `process_action'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/abstract_controller/base.rb:126:in `process'
/opt/rh/cfme-gemset/gems/actionview-5.0.0.1/lib/action_view/rendering.rb:30:in `process'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal.rb:190:in `dispatch'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_controller/metal.rb:262:in `dispatch'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_dispatch/routing/route_set.rb:50:in `dispatch'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_dispatch/routing/route_set.rb:32:in `serve'
/opt/rh/cfme-gemset/gems/actionpack-5.0.0.1/lib/action_dispatch/journey/router.rb:39:in `block in serve'


Version-Release number of selected component (if applicable):
----------------------
5.7.0.4


How reproducible:
----------------
Always


Steps to Reproduce:
-------------------
1.From the summary page of a cloud orchestration stack, click 'Parameters' in the Relationship section.


Actual results:
--------------
UI error


Expected results:
-----------------
No UI error


Additional info:
---------------