Di Gamemode

#define MYSQL_HOST                      "localhost"
#define MYSQL_USER                      "root"
#define MYSQL_DATABASE                  "gmdanial"
#define MYSQL_PASSWORD                  "private"

Di XAMPP

# password       = private

Di Log

[20:38:36] [ERROR] CConnection::CConnection - establishing connection to MySQL database failed: #1045 'Access denied for user 'root'@'localhost' (using password: YES)'
[20:38:36] [ERROR] CConnection::CConnection - establishing connection to MySQL database failed: #1045 'Access denied for user 'root'@'localhost' (using password: YES)'
[20:38:36] [ERROR] CConnection::CConnection - establishing connection to MySQL database failed: #1045 'Access denied for user 'root'@'localhost' (using password: YES)'
[20:38:36] [ERROR] CConnection::CConnection - establishing connection to MySQL database failed: #1045 'Access denied for user 'root'@'localhost' (using password: YES)'

1. Your password is somehow wrong (Assuming 'private' is just here to get us know that it is not exactly this one). 2. Your xampp phpmyadmin does not allow to connect via root. Try to unlock this or create new user with permissions to your data. You can also give us some more information. When this did happen, suddenly?