WHMCS - Critical Error: Could not connect to the database

Symptoms

When navigating to your WHMCS installation, you receive the following error:

Critical Error

Could not connect to the database.

Description and Solution

This error means WHMCS can not connect to the database. Usually, this is due to invalid database connection details or MySQL user privileges.

WHMCS suggests making sure the database connections details in configuration.php are correct and that the MySQL user assigned to the database has full access to it.

For more information and troubleshooting details, consider consulting WHMCS's documentation:

https://docs.whmcs.com/Database_Errors