On a Form with multiple required fields, the Publish button is unavailable, which is logical as the requirements are not fulfilled.
But entering just one character in one required field, makes the button available, even though the requirements are still not fulfilled.

Also related to #FT-136 , it would make it clearer for the user if they cannot press the button.

In my opinion, the button should visually be disabled (To indicate that you cannot submit), but still clickable (to allow to use it as a helper to point the user to the issue).
When clicked it would display the "is required" hints on the non-filled elements, to inform the user about why the Publish action is unavailable.