<!-- Access denied for user 'mcmain'@'localhost' (using password: YES) -->
Recently let a staff member go. Switching all passwords for security. I changed /library/config to the necessary database, user and user password so that XenForo knows that database to load for the webpage.
I believe it is some sort of privileges error.
In phpMyAdmin it lists 3 users under privileges for this database. I will list these below.
(user - host - type - privileges - grant)
mysql - localhost - global - all privileges - yes
root - local host - global - all privileges - yes
xenforo - local host - global - all privileges - no