Hi I wonder why jQuery in 3.6 is…

Hi.
I wonder why jQuery in 3.6 is v1.10.2. When I change themes and refresh the front page, error message pops up, saying “blockUI requires jQuery v1.3 or later! Your are using v1.10.2”. I downloaded the English WP 3.6 and checked the jquery.js in the folder “\wp-includes\js\jquery” and it really is v1.10.2.