Report no backend running if front end fails to get token validation

[amir-zeldes]

Currently if the UI is running but backend it not up yet, the token is not accepted but there is no verbose explanation of the problem (backend not found)

[Abhishek-P]

It may make sense to add some indication that backend up status, and then explicit error for token verification.
I didn't see any submit button either which is wierd too.