I had the same issue with not being able to do the update via USB connection to my computer. I kept getting an error saying unable to install update response -3. I finally did what was mentioned below and did the update from the device itself and it worked. While I'm glad I got passed that, it's still been extremely frustrating the amount of bugs the stadium has for a unit that costs $2,199.99. From the moment I got it there has been bug after bug. I didn't get my first Helix until it had been out for several years so maybe it had lots of issues out of the gate too, but I never saw those. This is pretty ridiculous.
All that being said, once you can get past the interface bugs, the unit works great. Hopefully they get this stuff worked out soon.