I recently imported a data model to be trained to use as part of the Predictive Subject Line option. I also imported the subjectlinetraining.xml and ran the technical workflow.
However, when I go to create an email delivery Subject Line, I do not see the 'Test subject button' as outlined in the documentation.
Adobe Campaign Help | Personalizing the subject line of an email
Am I missing something? Here's a screen shot showing - completion - of the data model I loaded.
And screenshot of the XML technical workflow completed: