How to switch to running off cellular
Oh - my. It's panic stations time.
You've installed a media player in a location outside your control. The networking professionals for the building are not able to provide dedicated wireless connectivity, nor a hard-line connection.
This is actually a very common problem. It is a regular occurrence at tradeshow exhibits.
Here's how you switch to cellular connectivity. First, TURN OFF the media player:
Congratulations! You're now booting from the USB key - and will shortly be connecting to the internet over cellular!
It takes about 10-15 minutes to boot from USB when you switch to cellular the first time.