FYI
Updated two XRS4500 by updating with 2015 but experienced problem with updates on each box
Box A: while updating and after 5 logo the box when into blue screen. Waited about 5 minutes but the screen was still stuck on blue screen so I have to power cycle the box in order for the box to boot properly.
Box B: while updating and after 5 logo on the screen, the box informed me that the BuzzTV crashed. I had to power cycle the box to boot properly.