I'm experiencing some known issues in earlier versions of Errai (mentioned here: [2.3.1.Final] Errai keeps reconnecting ([errai] http session has expired. resetting bus and attempting reconnection.)).
I'm using Errai 3.0.3.Final in a Wildfly 8.0.2.Final. The app gets deployed just fine but this is what I can see in the browser's console logs: http://pastebin.com/9JLgvtC5
It looks like you have a security configuration that doesn't allow requests to the server-side message bus (i.e. /out.55647-12652.erraiBus?z=501&clientId=55647-1265).
See the 401 (unauthorized) errors in the log you've shared.
|Retrieving data ...|