I found the answer on the php site: http://php.net/manual/en/function.empty.php
Prior to PHP 5.5, empty() only supports variables; anything else will result in a parse error. In other words, the following will not work: empty(trim($name)). Instead, use trim($name) == false.
Since MySQLi is object oriented and uses Classes and Methods, empty() won't work prior to php 5.5. It appears this issue has been resolved in more recent versions of PHP and will begin working again.