Ques. about how FICO scores are generated

[Bienes Raices]

I recently had a rental applicant who had credit history going back at least five years. There were 18 items in collection, none current. But the Transunion report didn't give a FICO score--it said there wasn't enough credit history to generate one. I don't see how this person could not have a score at this point. Do they have to have at least one positive item for the score to be generated?