When you add new prototypes, you have to modify several files:
In the Specs folder, portraits.xml has to have the correct TEXT and UNIT parameter. Those coincide with the Unit.xml Unit ID and strings in the Lang folder files portraits.xml and infotexts.xml.
Specs portraits.xml
<portrait prototype="mod:Prototypes/Persons/02 EPI/urbano.e4p" big="norm" text="LISBONENSE" unit="LISBONENSE"/>
Lang portraits.xml
<string name="ID_PORTRAIT_LISBONENSE>Display Name Goes Here</string>
Lang infotexts.xml
<string name="ID_NAME_LISBONENSE">Display Name Goes Here</string>
<string name="ID_PURPOSE_LISBONENSE">Description Goes Here</string>
<string name="ID_TOOLTIP_LISBONENSE">Display Name Goes Here</string>
Make sure you've also copied over the image files into the same unit folder.