Why Won’t Firefly Load Prompts With Nationalities?

What is wrong with the following prompt that Firefly refuses to load it? How can I make this a better prompt to create a diverse tech team?

A 5-person cast for a book cover: a young Caucasian-American male in a lab coat with dark brown hair and stylish glasses. A young Asian American who wears designer clothes that are casual but is a computer geek with sneakers that light up. A young fiery redhead who dresses as a cool computer nerd with ripped, tight black jeans but is stylish, a black band tee, and jacket without the hood part on and black combat boots. A young black American girl who has beautiful long braids that are side-swept, with an urban style that includes bright colors, graphic tees with her own designs, and funky sneakers. A young Hispanic male with jeans, t-shirts, and a lab coat. These are a group of young scientists and tech nerds. On a dark background with the skyline of downtown Dallas behind them the cast of people since the story takes place in Dallas Texas. Use the blended styles of graphic art, oil painting, and digital art.