the files that site sculptor creates can be in the root of your site or they can be in a sub directory.
Wherever they are placed, the containing folder needs to allow read and write access for all users.
if they are in the root, you need to set the access level for the site root to allow read and right access for all users, either 755 or 777 permission level.
if you place the site sculptor files in a sub directory, that sub directory needs to have read and write permissions granted for all users.