Problem
You can't add new content, if the entity requires an preview first. The save button don't show up.
Reproduce the bug:
- login as administrator
- open admin/structure/types/manage/page
- Submission form settings > Preview before submitting > set required and save
- create new content node/add/page
- the blue save button didn't appear, even after the preview
Expectation / Suggestion
The "Save and publish" button should show up, once the preview was seen.
Eventually a save button within the preview would solve the problem as well.