Upgrade error WordPress 3.6 Genesis 2.0.0

I recently upgraded to 3.6 and use Studiopress themes and the Genesis framework.

When I updated Genesis today to the new 2.0.0 version I got the same issues as another post here: https://www.ads-software.com/support/topic/error-after-update-36?replies=6

The site is still functioning thankfully but when I go to the Pages or Posts sections in my dashboard I have this error message showing up under each page/post entry:

My error reads:

Warning: htmlspecialchars() [function.htmlspecialchars]: charset `UTF-7′ not supported, assuming iso-8859-1 in /home/seovirgi/public_html/wp-includes/formatting.php on line 2751

I deactivated all plugins and then reverted back to the Twenty Thirteen theme to rule out plugins and themes and the problem continues.

There is something amiss with WordPress 3.6 + Genesis 2.0.0

Any input would be great