#26805 introduced a new helper app_metadata which seems to always render 500, as it calls per_page_options which seems undefined

here's the whole trace

2019-06-10T02:29:57 [I|app|7af10402] Started GET "/katello/sync_management" for 10.40.204.140 at 2019-06-10 02:29:57 -0400
2019-06-10T02:29:57 [I|app|7af10402] Processing by Katello::SyncManagementController#index as HTML
2019-06-10T02:29:57 [I|app|7af10402] Current user set to admin (admin)
2019-06-10T02:29:57 [I|app|7af10402]   Rendering /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/index.html.erb within katello/layouts/katello
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_controls.html.erb (0.5ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered collection of /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_repo.html.erb [1 times] (1.1ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered collection of /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_repo.html.erb [1 times] (0.9ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_children.html.erb (1.3ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered collection of /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_repo.html.erb [1 times] (0.9ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_children.html.erb (1.3ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_children.html.erb (3.2ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered collection of /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_repo.html.erb [1 times] (0.9ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered collection of /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_product.html.erb [16 times] (9.8ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/_products.html.erb (11.1ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendered /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/sync_management/index.html.erb within katello/layouts/katello (18.4ms)
2019-06-10T02:29:57 [I|app|7af10402]   Rendering layouts/base.html.erb
2019-06-10T02:29:58 [I|app|7af10402]   Rendered layouts/base.html.erb (663.0ms)
2019-06-10T02:29:58 [W|app|7af10402] Action failed
ActionView::Template::Error: undefined local variable or method `per_page_options' for #<#<Class:0x00007f4bd5119518>:0x0000000010cbb8c0>
/usr/share/foreman/app/helpers/application_helper.rb:532:in `app_metadata'
/usr/share/foreman/app/helpers/layout_helper.rb:3:in `mount_react_app'
/usr/share/foreman/app/views/layouts/base.html.erb:59:in `block in _fc5f29b2ef60dc43b37cd6c264710df9'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/helpers/cache_helper.rb:253:in `write_fragment_for'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/helpers/cache_helper.rb:243:in `fragment_for'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/helpers/cache_helper.rb:169:in `cache'
/usr/share/foreman/app/views/layouts/base.html.erb:58:in `_fc5f29b2ef60dc43b37cd6c264710df9'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:159:in `block in render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:170:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:354:in `instrument_render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:157:in `render'
/opt/theforeman/tfm/root/usr/share/gems/gems/deface-1.3.2/lib/deface/action_view_extensions.rb:41:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:54:in `block (2 levels) in render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/abstract_renderer.rb:44:in `block in instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:168:in `block in instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications/instrumenter.rb:23:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:168:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/abstract_renderer.rb:43:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:53:in `block in render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:61:in `render_with_layout'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:52:in `render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:16:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/renderer.rb:44:in `render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/renderer.rb:25:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/helpers/rendering_helper.rb:33:in `render'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/app/views/katello/layouts/katello.html.erb:23:in `_f3db49166c2727eb8a1af25a058bc5f2'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:159:in `block in render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:170:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:354:in `instrument_render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/template.rb:157:in `render'
/opt/theforeman/tfm/root/usr/share/gems/gems/deface-1.3.2/lib/deface/action_view_extensions.rb:41:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:66:in `render_with_layout'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:52:in `render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/template_renderer.rb:16:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/renderer.rb:44:in `render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/renderer/renderer.rb:25:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/rendering.rb:103:in `_render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/streaming.rb:219:in `_render_template'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/rendering.rb:84:in `render_to_body'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/rendering.rb:52:in `render_to_body'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/renderers.rb:142:in `render_to_body'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/abstract_controller/rendering.rb:25:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/rendering.rb:36:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:46:in `block (2 levels) in render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/core_ext/benchmark.rb:14:in `block in ms'
/opt/rh/rh-ruby25/root/usr/share/ruby/benchmark.rb:308:in `realtime'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/core_ext/benchmark.rb:14:in `ms'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:46:in `block in render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:87:in `cleanup_view_runtime'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activerecord-5.2.1/lib/active_record/railties/controller_runtime.rb:31:in `cleanup_view_runtime'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:45:in `render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/implicit_render.rb:35:in `default_render'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/basic_implicit_render.rb:6:in `block in send_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/basic_implicit_render.rb:6:in `tap'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/abstract_controller/base.rb:194:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/rendering.rb:30:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/abstract_controller/callbacks.rb:42:in `block in process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:109:in `block in run_callbacks'
/usr/share/foreman/app/controllers/concerns/foreman/controller/timezone.rb:10:in `set_timezone'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:118:in `block in run_callbacks'
/usr/share/foreman/app/controllers/concerns/foreman/controller/topbar_sweeper.rb:12:in `set_topbar_sweeper_controller'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:118:in `block in run_callbacks'
/opt/theforeman/tfm/root/usr/share/gems/gems/audited-4.7.1/lib/audited/sweeper.rb:14:in `around'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:118:in `block in run_callbacks'
/opt/theforeman/tfm/root/usr/share/gems/gems/audited-4.7.1/lib/audited/sweeper.rb:14:in `around'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:118:in `block in run_callbacks'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:136:in `run_callbacks'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/abstract_controller/callbacks.rb:41:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/rescue.rb:22:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:34:in `block in process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:168:in `block in instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications/instrumenter.rb:23:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/notifications.rb:168:in `instrument'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/instrumentation.rb:32:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal/params_wrapper.rb:256:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activerecord-5.2.1/lib/active_record/railties/controller_runtime.rb:24:in `process_action'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/abstract_controller/base.rb:134:in `process'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionview-5.2.1/lib/action_view/rendering.rb:32:in `process'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal.rb:191:in `dispatch'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_controller/metal.rb:252:in `dispatch'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/route_set.rb:52:in `dispatch'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/route_set.rb:34:in `serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:52:in `block in serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:35:in `each'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:35:in `serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/route_set.rb:840:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/engine.rb:524:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/railtie.rb:190:in `public_send'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/railtie.rb:190:in `method_missing'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/mapper.rb:19:in `block in <class:Constraints>'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/mapper.rb:48:in `serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:52:in `block in serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:35:in `each'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/journey/router.rb:35:in `serve'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/routing/route_set.rb:840:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/apipie-rails-0.5.14/lib/apipie/static_dispatcher.rb:65:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/apipie-rails-0.5.14/lib/apipie/extractor/recorder.rb:137:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/usr/share/foreman/lib/foreman/middleware/telemetry.rb:10:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/apipie-rails-0.5.14/lib/apipie/middleware/checksum_in_headers.rb:27:in `call'
/usr/share/foreman/lib/foreman/middleware/catch_json_parse_errors.rb:9:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/tempfile_reaper.rb:15:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/etag.rb:25:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/conditional_get.rb:25:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/head.rb:12:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/http/content_security_policy.rb:18:in `call'
/usr/share/foreman/lib/foreman/middleware/logging_context_session.rb:22:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/session/abstract/id.rb:232:in `context'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/session/abstract/id.rb:226:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/cookies.rb:670:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/callbacks.rb:98:in `run_callbacks'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/callbacks.rb:26:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/debug_exceptions.rb:61:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/rack/logger.rb:38:in `call_app'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/rack/logger.rb:28:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/sprockets-rails-3.2.1/lib/sprockets/rails/quiet_assets.rb:13:in `call'
/usr/share/foreman/lib/foreman/middleware/logging_context_request.rb:11:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/request_id.rb:27:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.13.0.pre.master/lib/katello/prevent_json_parsing.rb:12:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/method_override.rb:22:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/runtime.rb:22:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/activesupport-5.2.1/lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/executor.rb:14:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/actionpack-5.2.1/lib/action_dispatch/middleware/static.rb:127:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/sendfile.rb:111:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/secure_headers-6.0.0/lib/secure_headers/middleware.rb:13:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/engine.rb:524:in `call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/railtie.rb:190:in `public_send'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/railties-5.2.1/lib/rails/railtie.rb:190:in `method_missing'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/urlmap.rb:68:in `block in call'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/urlmap.rb:53:in `each'
/opt/theforeman/tfm-ror52/root/usr/share/gems/gems/rack-2.0.6/lib/rack/urlmap.rb:53:in `call'
/usr/share/passenger/phusion_passenger/rack/thread_handler_extension.rb:74:in `process_request'
/usr/share/passenger/phusion_passenger/request_handler/thread_handler.rb:141:in `accept_and_process_next_request'
/usr/share/passenger/phusion_passenger/request_handler/thread_handler.rb:109:in `main_loop'
/usr/share/passenger/phusion_passenger/request_handler.rb:455:in `block (3 levels) in start_threads'
/opt/theforeman/tfm/root/usr/share/gems/gems/logging-2.2.2/lib/logging/diagnostic_context.rb:474:in `block in create_with_logging_context'
2019-06-10T02:29:58 [I|app|7af10402]   Rendering common/500.html.erb within katello/layouts/katello
2019-06-10T02:29:58 [I|app|7af10402]   Rendered common/500.html.erb within katello/layouts/katello (1.6ms)
2019-06-10T02:29:58 [I|app|7af10402] Completed 500 Internal Server Error in 996ms (ActiveRecord: 38.1ms)
2019-06-10T02:29:58 [F|app|7af10402]   
2019-06-10T02:29:58 [F|app|7af10402] ActionView::Template::Error (wrong number of arguments (given 1, expected 0)):
2019-06-10T02:29:58 [F|app|7af10402]     1: <%= alert :header => _("Oops, we're sorry but something went wrong"), :class => 'alert-danger',
    2:   :actions => link_to(_('Back'), main_app.root_path, :class => 'btn btn-default'),
    3:   :text => h(exception.message),
    4:   :close => false %>
2019-06-10T02:29:58 [F|app|7af10402]   
2019-06-10T02:29:58 [F|app|7af10402] app/views/common/500.html.erb:1:in `_9f464734c34179471d1d26633a690a74'

Assigning Gilad who knows, how the helper works, but feel free to reassign.