I just wanted to let know everybody who is planning to upgrade their default theme to ultimate-theme1. As you probably know this theme can be purchased outside the KVS but is fully integrated into the system. The upgrade is straightforward BUT you need to be aware of the robots.txt file. Please check whether it allows bots (including google) to crawl your website.
I came across significant visitors drop after the theme upgrade and started to investigate. After checking some main keywords on google I found out that almost all results I used to have on google were gone and those who were there included google comments that the robots.txt file is blocking the website for crawling. So, I tested my website with the google robots.txt test tool which showed me User-agent: * Disallow: /
So, what you need to do if it is your case too, is just change your robots.txt file, upload it to your server then submit your new file to google on the same tester tool page. Do not forget to submit your sitemap file as well, so google will know that there are changes.
Now, I am starting to see visitors coming back, but I believe it will take some time for google to re-crawl the whole website.