The "initial login for script" is not adding the admin user after installing WHMCS. After installation, it reports:
Now installing WHMCS version 5.2.15 ..
Account creation did not succeed More information on using this script can be found at http://www.whmcs.com/members/aff.php?aff=4115.
.. installation was only partially complete.
Applying web server configuration .. .. done
Checking the WHMCS database, the tbladmins table is empty.
Also the latest install script for WHMCS is 5.2.15, the latest version is 5.3.7