Originally Posted by easyhostmedia
have you enabled
SQL Debug Mode
Hooks Debug Mode
in General > Other in your WHMCS admin area, this will then display where the error is.
also dont forget you need to install in Binary
SQL debug mode would be irrelevant at this stage and there is no way he will be able to enable that setting via the admin area given the fact he is on the installation stage.
@OP: Edit your configuration.php file and add the following 2 lines of code at the bottom (but before the closing PHP tag):
$display_errors = true;
$display_errors = E_ALL ^ E_NOTICE;
That should make whatever is causing the issue appear. I'm going to take a guess and assume it is related to ioncube but we will see