Error Message during Template Install – No access to /wp-admin/update on server

I’ve just purchased a template from templatic.com. I’ve been really excited and waiting to use it. However, I received the following error message after trying to install it. I need help. I really want to use the product. Has anyone had this problem? Does anyone know how to fix this problem?

——- Error Message Below ———

Are you sure you want to do this?

Please try again.
Forbidden

You don’t have permission to access /wp-admin/update.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.