A customer upgrade failed, logging this:
[24/Oct/2013:13:52:52 +1300] category=UPGRADE sq=54 severity=SEVERE src=org.opends.server.tools.upgrade.UpgradeUtils updateSchemaFile
msg=The attribute emailAddress doesn't exist in the template configuration
[24/Oct/2013:13:52:52 +1300] category=UPGRADE sq=55 severity=INFO src=org.opends.server.tools.upgrade.UpgradeTasks displayChangeCount
msg=...No change applied in /opt/opendj/config/schema/00-core.ldif
It isn't clear how the attribute was missing - perhaps a problem during the unzip? - but the behaviour in updateSchemaFile() is to ignore the problem and effectively write zero changes to the schema file. This is considered a "success" by the upgrade UI, and it really should be an error.