Lin makes ice cream for dogs. Wanting to start her own business, Lin gets a food truck, and starts driving around different neighborhoods peddling her doggy ice cream using the business name "Tasty Ice." Her business is going great until her clients learn that Lin doesn't have the required license to sell anything from a truck and so they want to get their money back saying the contracts were unlawful. Can the clients void the prior contracts with Lin due to the lack of a license