Most of the module set-up screens have a notice at the bottom saying "There are required fields in this form marked*" but since the notice is always there, most people do not pay attention to it. Particularly problematic is the fact that the required fields are invariably at the TOP of the form, while the save button and the notice are at the BOTTOM.
The user thus can click on "submit" and sit there wondering why nothing is happening. Now, if the notice appeared (as it does in many other web applications) ONLY after a save was attempted on an incomplete form, users would then know exactly what they need to do. [Even this tracker application has this feature!]