I'm not sure on the logging issue, but lets try this for now to find out what the SQL error is. Just a quick edit to the changebasic.php file. Down at the very bottom, you'll see this:
// ---------------------------------------------------
// Send them to their start page with the confirmation
$html -> start_page($Cat);
Right before that, add this:
exit;
That will make it so it doesn't forward you to the next page so you can actually copy and paste the error here.