array() expects parameter 1 to be a valid callback, function ‘

I m an beginner and getting the below error how to fix it.it gives an error every time i try to add a new page. can any one help??

arrayy() expects parameter 1 to be a valid callback, function ‘shop_isle_custom_add_save’ not found or invalid function name in C:\xampp\htdocs\dr.krishnadance\wp-includes\class-wp-hook.php on line 300