To fix this issue you need to check if:
The file starter-gatein.ear (which will be starter.war for Tomcat) has been deployed
The file starter-gatein.ear (which will be starter.war for Tomcat) is the last ear file to be launched
With Tomcat to prevent any alphabetic issue, the good way to solve this problem is to:
Unzip the archive starter.war into a directory called starter
Remove the archive starter.war
Rename the folder starter to starter.war
This tip works because folders corresponding to unzipped wars are launched after war files.