Apologies I cannot give you a link to the site as it is not appearing on the web.
I was in Google Webmaster yesterday trying to post the verification code to have the site recognized by Google, I posted the code into my sitemap and Google could not recognize it. After this the site disappeared from the search engine. Does this help?
Tried to revert to default and that did not work.
I altered the code in the header file, once it did not work I took out the code that I had copied over from Google Webmaster
I went into appearance page then editor and posted the code from Google Webmaster – this was not then recognized by Google, so I went back in and took the code out. That is when the site disappeared from view.
I’d suggest using a plugin for SEO – is that what you are doing?
And when you say your site has disappeared, do you mean is it not accessible on the front end or that it is not in Google Search results? I’d certainly sort out the first one first.