Why "Whitelabel Error Page" appear in spring XD?

I'm on windows 7

trying to follow spring XD twitter analytics dashboard project instructions

http://ift.tt/1vuczDm

streaming twitter data works fine, I've reached the final stage which is

 spring run dashboard.groovy

but when I access

  http://localhost:8080/dashboard.html 

this error page appear

 Whitelabel Error Page

 This application has no explicit mapping for /error, so you are seeing this as a fallback.

 There was an unexpected error (type=Not Found, status=404).

Please help.