You may use this function IF not all slots are assigned with invigilators.

To Force-Assign Invigilator Minimum Load, click Force Assign Invigilator Minimum Load icon at Invigilator under Generate Options Tab.

Diagram 3.2.1 Force Assign Invigilator Minimum Load Location

A confirmation popup will appear. Click Yes.

Diagram 3.2.2 Confirmation Popup

Once done, another popup will appear saying it has been completed.

Diagram 3.2.3 Completion Popup