[Satellite6] An error occurred saving the Repository: undefined method `content_id' for nil:NilClass Did you mean? contains_erb?

Issue

When trying to save changes done to a custom repository an error is displayed in the webui:

An error occurred saving the Repository: undefined method `content_id' for nil:NilClass Did you mean? contains_erb?

The repository update task fails

Actions::Katello::Repository::Update

undefined method `content_id' for nil:NilClass
Did you mean?  contains_erb? (NoMethodError)
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.7.0.46/app/lib/actions/katello/repository/update.rb:15:in `plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/action.rb:493:in `block (3 levels) in execute_plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:26:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware.rb:18:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman-tasks-0.13.4.3/app/lib/actions/middleware/keep_current_user.rb:10:in `block in plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman-tasks-0.13.4.3/app/lib/actions/middleware/keep_current_user.rb:31:in `with_current_user'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman-tasks-0.13.4.3/app/lib/actions/middleware/keep_current_user.rb:9:in `plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:22:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:26:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware.rb:18:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware.rb:35:in `plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:22:in `call'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:26:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware.rb:18:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware.rb:35:in `plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.0.5.5/lib/dynflow/middleware/stack.rb:22:in `call'

• The error can also be:

undefined method `name' for nil:NilClass (NoMethodError)
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.10.0.58/app/lib/actions/katello/repository/update.rb:18:in `plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.1.6.1/lib/dynflow/action.rb:493:in `block (3 levels) in execute_plan'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.1.6.1/lib/dynflow/middleware/stack.rb:26:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.1.6.1/lib/dynflow/middleware.rb:18:in `pass'
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.1.6.1/lib/dynflow/middleware.rb:35:in `plan'