Steps to reproduce

1. Log in to back office.
2. Go to Content / Content types.
3. Start creating a new CT.
4. Add matrix fieldtype to field definition.
5. Expand added fieldtype.
6. Add two new rows in columns section. (do not fill added rows).
7. Click on 'Save' button.

Actual result:

• User is redirected to the same form.
• No validation information that added rows cannot be empty

Expected result:

Validation message / validation inform user which fields have to be filled.