Grails prod war not work

[liuxiaoyi]

Hi,
When I run command : grails prod war , I received following error message:
java.lang.NullPointerException: Cannot invoke method getAt() on null object
at grails.util.BuildSettings.configureDependencyManager(BuildSettings.groovy:1259)
at grails.util.BuildSettings$configureDependencyManager.callCurrent(Unknown Source)
at grails.util.BuildSettings.postLoadConfig(BuildSettings.groovy:1170)
at grails.util.BuildSettings.loadConfig(BuildSettings.groovy:1068)
at grails.util.BuildSettings.loadConfig(BuildSettings.groovy:1050)
at grails.util.BuildSettings$loadConfig.callCurrent(Unknown Source)
at grails.util.BuildSettings.loadConfig(BuildSettings.groovy:1028)
| Error There was an error loading the BuildConfig: Cannot invoke method getAt() on null object

Could you help me to understanding what's wrong with my envirement?
(ubuntu1604 /jdk1.7/grails2.2.5)

by the way , when I try to download war file from dropbox directly , the page shows 404

thank you !
Eric Liu