Hi jamboknight,
You should have received the 360 remotes before you were upgraded, you get the remotes and then start the upgrade yourself is the preferred method, the upgrade will download to the V6 box and do the upgrade itself after 5 days, sounds like this may have happened.
Error 408 is a Wi-Fi network error, you might need the 360 remotes to reconnect, you could try using a ethernet cable until you receive them, you will need to call Virgin on 150 from a Virgin phone, mobile or landline, or 0345 454 1111 from any other phone to ask for your remotes or wait here for one of the forum team team to pick this up which might be 2 to 3 day's.
The instructions should could with the remotes if not, this is from this Page
Upgrading V6 boxes to 360
Sort the first V6 box yourself > Let the 2nd V6 box upgrade itself > Install any Virgin TV 360 Mini box
1.. Turn on all V6 boxes: take your current TV boxes off standby and check they’re connected to the internet, ready to download TV 360.
2. Pop the telly on: check its set to the correct Input and Virgin TV’s playing.
3. Grab its old V6 remote control: tap the Home button, select Apps & Games > Upgrade To Virgin TV 360 Now > OK.
4. Follow the instructions on your telly: when you see it’s ‘Time to make the big switch’, remove the red tab from just one new 360 remote (doesn’t matter which).
**Nothing happening? **
Try pressing OK on the new 360 remote. Or grab the V6 remote again, press the red button and enter 847446 (the verification code) to start the upgrade.
If the new remote doesn’t work when the upgrade’s finished (it should), try pointing it at the TV box: hold down the TV and 0 buttons together for 10 seconds (may take a few tries). Remember to use the 2nd 360 remote for the 2nd TV box, when it’s upgraded itself.
