After setting up a new site in Plesk and restarting Apache, the site would only display 403 Forbidden errors. The same error occured whether we went to the exclusive IP address or the domain name so we knew that it wasn’t a DNS problem. We checked the logs and it showed that Apache was unable to read the .htaccess file. We changed the permissions on this file, which didn’t do any good.
It turned out that when Plesk set up the domain, it gave the httpdocs directory the wrong permissions. Instead of the permissions that it assigned it, we changed it to 755 or rwxr-xr-x and everything works now.
If you get permission errors in the future, be sure to check the directory the file belongs in as well.