Once the game loads:
"Players have black heads / missing boots." Fix: You didn't apply the mod correctly. Uncheck the mod in FIFA Mod Manager, close the app, re-open it, and re-apply. Also, ensure your FIFA 23 is updated to the exact version the patch requires.
: The base FIFA 23 contains roughly 17,000 players. A major classic patch can add 10,000–15,000 historical players, each with carefully researched attributes (pace, shooting, physicality, etc.), weak foot ratings, skill moves, work rates, and even custom faces for legends. This requires sifting through match footage, statistical archives, and subjective fan consensus to recreate the essence of, say, Gerd Müller or Paolo Maldini.