While trying to create a new build:

end up at URL - http://localhost:8085/build/admin/create/createBuildBuilder.action

in the builder configuration tab, fill in the details and click next:

"Cannot find or execute 'null' at 'null'"

The console output of the appserver is:
2006-11-28 04:53:08,664 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.type.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,757 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.common.tests.exists.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,791 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.ant.buildFile.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,795 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.ant.target.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,817 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.common.tests.exists.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,876 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.common.tests.exists.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,907 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.common.tests.exists.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,962 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.script.script.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'
2006-11-28 04:53:08,974 WARN [SocketListener0-1] [LocalizedTextUtil] Unable to find text for key 'builder.common.tests.exists.description' in 'class com.atlassian.bamboo.ww2.actions.build.admin.config.ConfigureBuildBuilder' and locale 'en'

I've included a screenshot, so you can see the values I'm entering.

Cheers,

Ben