The Google Webmaster Tools has a bug in it that will not allow you to set your “Preferred domain”. The error goes like this:
Part of the process of setting a preferred domain is to verify that you own http://www.yourdomain.com/. Please verify http://www.yourdomain.com/.
The purpose of this tool is to set your canonical domain. For example you could chose to have you site listed in the Google Results Page as:
www.yourdomain.com
Or
yourdomain.com
The explanantion for this tool is from Google”
The preferred domain is the one that you would like used to index your site’s pages. If you specify your preferred domain as http://www.example.com and we find a link to your site that is formatted as http://example.com, we’ll treat that link as if it was http://www.example.com. In addition, we’ll take your preference into account when displaying URLs in our search results. It may take some time for changes to be reflected in our index.
Basically the reason to use this tool is prevent inconsistent URL structure and prevent Google from treating www.yourdomain.com OR yourdomain.com as two different pages. Another reason is to control whether you want you domain listed in the search results as www.yourdomain.com OR yourdomain.com. Seemingly most people tend to use the www. version. There is no real best practice here, as the www does nothing more than provide what people are more used to seeing.
THE FIX
1) Submit bit versions of your site:
www.yourdomain.com
yourdomain.com
Even though these are the same site we need to submit both version for some funny reason. I discovered this fix late at night when I was not paying close attention. I found this work around by accident.
2) Verify within the Google Webmaster Tools both canonical versions of your site, i.e. www.yourdomain.com AND yourdomain.com. You will use the same verification code for both sites.
3) Now select your preferred canonical version , eg www.yourdomain.com.
You should now see the verification process complete normally.
4) Delete the other site from the webmaster tools. In this case we verified the www. version so we now remove the non www version.
I have no idea how a bug like this can happen and for how many people this must be annoying. I searched all the Google sites and there was little to no information on this subject.
