When you install WHMCS on a server, make sure to watch for errors both during and after the installation process.
Troubleshoot and resolve 1062 Duplicate entry for key tblconfiguration.PRIMARY errors.
Troubleshoot and resolve A license key is required. errors during installation.
Troubleshoot and resolve the messages that stop a new WHMCS installation when the configuration.php file already contains database details.
Troubleshoot and resolve issues that cause the WHMCS installation process to stop on Step 4.
Troubleshoot and resolve The installer refused the administrator password errors.