Before scanning the head, you will need to load a DNA type, which determines whether the face is to be considered as symmetrical or asymmetrical.
The DNA matters for when you're:
Picking the landmark points on the face (Stage 3: Landmarks).
Tuning the soft tissue deformers on the face (Stage 6: Tune).
If you have Symmetry as the DNA type, you only have to work on one side of the face (the face's left side) to affect both sides at the same time.
If you have Asymmetry defined, you need to work on each side of the face separately.
Click the Library Type tab and click the browser (…) button.
In the browser, go to the folder where the DNA files are located and select that folder. You can set the default path to these files in the Face Robot Preferences [Preference Reference].
On the Type tab, select the type of head (its DNA file):
Click the Apply button. The Type you have selected is displayed at the bottom of the Assemble panel.