I am having trouble installing CubeCart on my reseller. I go through steps 1-3 fine and I click the button to proceed to step 4, but all it does is display a blank page. Viewing the source code I get this:

CODE
<!--#set var="title" value="403 Forbidden" -->
<!--#set var="msg" value="Access is forbidden to the requested page:" -->
<!--#include virtual="cp_errordocument.shtml" -->


And if I refresh the page then it tells me the permissions on my configuration file is incorrect. How do I remedy this error?