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