Bug 1360771

You can delete a tasks using, maybe replacing the label.

# foreman-rake console  
ForemanTasks::Task.where(:state => :stopped).where(:label => "Actions::Katello::Repository::Sync").destroy_all

Upstream bug assigned to jsherril

OK hitting this myself and raised a dupe BZ#1364768 as my search-foo was not great.

Now how to resolve it ?

*** Bug 1364768 has been marked as a duplicate of this bug. ***

I managed to fix this (or workaround it at least) by applying this:-

https://github.com/Katello/katello/pull/6028

Cleared sessions & katello-service restart

I've same error, and decided updating file /opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.0.0.68/app/models/katello/content_view_history.rb

line ~45 

-def humanized_action
-  case self.task.label
-  when "Actions::Katello::ContentViewVersion::Export"
-    _("Exported version")
-  when "Actions::Katello::ContentView::Publish"
-    _("Published new version")
-  when "Actions::Katello::ContentView::Promote"
-    _("Promoted to %{environment}") % { :environment => self.environment.name }
-  when "Actions::Katello::ContentView::Remove"
-    _("Deleted from %{environment}") % { :environment => self.environment.name }
-  end
-end

+def humanized_action
+  case self.task.try(:label)
+  when "Actions::Katello::ContentViewVersion::Export"
+    _("Exported version")
+  when "Actions::Katello::ContentView::Publish"
+    _("Published new version")
+  when "Actions::Katello::ContentView::Promote"
+    _("Promoted to %{environment}") % { :environment => self.environment.try(:name) || _('Unknown') }
+  when "Actions::Katello::ContentView::Remove"
+    _("Deleted from %{environment}") % { :environment => self.environment.try(:name) || _('Unknown')}
+  else
+    _("Unknown Action")
+  end
+end


Clear all tasks in DynFlow, database and pulp.
Restart all services.

*** This bug has been marked as a duplicate of bug 1361793 ***