You wouldn't get the error you reported on this page:
Notice: Undefined index: perm in /home/motle7bk/public_html/clients/equicraft/shop-product-details_s.php on line 97
since the perm parameter is clearly set.
A blank page with error reporting turned on usually means a syntax error. An open quote or open parenthasis or bracket without the close. You'll have to systematically remove code to figure out where the error occurs and either get an error message or narrow down the line that causes the error in order to debug it.