Delivered Parameter: mysql:host=localhost;dbname=user17;charset=utf8mb4

Database Connection failed: SQLSTATE[HY000] [1698] Access denied for user 'user17'@'localhost'

Check:
- You have already installed the Ranksystem? Run install.php first!
- Is the database reachable?
- You have installed all needed PHP extenstions? Have a look here for Windows or Linux?