Why can I test, but not release a model that has rules that aren't valid?

You can test a model that has a rule that isn't valid because the testing phase of creating a model provides you the opportunity to make each rule valid. Oracle Configurator won't allow you to release a model that contains a rule that isn't valid because that rule will prevent your user from creating a configuration that's valid.

If you don't fix an invalid rule, then you can disable that rule, and then release the model.