My hypothesis is that McAfee SiteAdvisor does not like Add-On domains. the problem may be that only TOP LEVEL Domains can be verified.
I'm basing that on the following....
I was able to verify my top level domain after I did the following.
This worked for TOP LEVEL domain:
- Deactivate all Plugins
- Use the default theme TwentyTen
- rename the .htaccess to .htaccessold
- Go Back to McAfee SiteAdvisor and click "Request Verification File"
* You should now see the McAfee Validation File name.
- Create the file and upload to your host in the root directory
- Go Back to McAfee SiteAdvisor and click the "Verify" Button
- rename the .htaccessold to .htaccess
However, I tried the same steps for one of my add-on domains and I still go the error Site returning an HTTP 2xx or 3xx status response code in the header of 404 pages.
I deleted the site and installed completely from scratch. I deleted both the default plugins (askimet and Hello dolly) and I renamed the .htaccess file.
An Addon Domain is a domain name that points to a different subdirectory on your account. This gives you the ability to make it look like an entirely different website.