Same issue here. Just started. I've also unplugged for about 10 mins, replugged into a wall outlet (no surge protector) and it keeps resetting. I did get to see about 30 seconds of live content before it rebooted again. Now it's in a permanent boot loop. If it matters I do have an OTA antenna hooked up.
Wait time on the help number was 46 minutes when I called into the 800-333-3474. Still waiting....
Follow-up status. I got through to phone support. She said they were having problems on the Dish side of the network.
They had me unplug the hopper, disconnect the coax cable to the dish, power back up and reconnect the coax while it was booting. She said this was to re-sync with the dish. It then booted, went through the satellite acquisition screen, and they then had me go in to settings (home button on the remote twice, and down arrow twice) and check that the prime time anytime was on.
If it happens again I'm supposed to call in again.