Even Millennium has quirks. Here are the most common Google searches regarding errors.
Extract the zip. You will see three critical folders: kz manager millennium
Upload all files respecting the directory structure. Even Millennium has quirks
Millennium pre-caches demo frames. If the server has 1000+ records, it may stutter. Request the admin to prune old demos older than 90 days. Upload all files respecting the directory structure
KZ Manager Millennium integrates with SQL databases (MySQL, PostgreSQL) to store global rankings. Many communities use a web interface that links directly to the plugin, allowing players to view their rank on a website, filter by friends, or watch demo replays of the top run.