Copy the data folder from the pack into your main FIFA 16 folder. If asked to overwrite, choose Yes (after backup).
Example: Stadium Pack V4 by FIFA Infinity – contains folders like data/sceneassets/stadium , data/ui , etc.
Save DB in CM16, then regenerate once more.
Open i68 Controller → Select FIFA 16 → Click Regenerate (full regeneration, not just BH). Alternatively, use Creation Master 16 → Tools → Regenerate BH Files .