For many types of issue, the first step in troubleshooting is enabling WHMCS's error reporting system.
WHMCS makes troubleshooting easier with built-in error handling.
The Module Queue list allows you to quickly find and retry failed automated actions.
WHMCS allows you to prune logs to reduce the size of the database and reduce disk space.
WHMCS logs all activity, admin logins, gateway communications, sent and received email communications, and domain lookups.
The Log tab in the Client Profile lists entries from the Activity Logs that relate to the client.
You can take steps to optimize performance on larger installations.