Some users' data causes the JIRA 2.5 upgrade task to fail. The exception in the log is:

2003-11-13 18:47:55,202 ERROR [atlassian.jira.upgrade.UpgradeManagerImpl] Exception thrown during upgrade: Passed List had more than one value.
java.lang.IllegalArgumentException: Passed List had more than one value.
at org.ofbiz.core.entity.EntityUtil.getOnly(EntityUtil.java:58)
at com.atlassian.jira.upgrade.tasks.UpgradeTask_Build56.doUpgrade(UpgradeTask_Build56.java:77)
at com.atlassian.jira.upgrade.UpgradeManagerImpl.doUpgradeTaskSucess(UpgradeManagerImpl.java:565)
at com.atlassian.jira.upgrade.UpgradeManagerImpl.doUpgrade(UpgradeManagerImpl.java:318)
at com.atlassian.jira.upgrade.UpgradeManagerImpl.doUpgradeIfNeeded(UpgradeManagerImpl.java:264)
at com.atlassian.jira.upgrade.UpgradeManagerImpl.doUpgradeIfNeededAndAllowed(UpgradeManagerImpl.java:252)
at com.atlassian.jira.action.admin.DataImport.doExecute(DataImport.java:90)
at webwork.action.ActionSupport.execute(ActionSupport.java:154)
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:46)
at com.atlassian.jira.action.JiraNonWebActionSupport.execute(JiraNonWebActionSupport.java:34)
at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:131)

However JIRA works normally after this, until the user next restarts JIRA. Then they get this exception:

2003-11-13 18:55:25,312 ERROR [atlassian.jira.upgrade.UpgradeManagerImpl] Exception thrown during upgrade: Could not upgrade due to non default statuses. Please contact support@atlassian.com for more information.
java.lang.Exception: Could not upgrade due to non default statuses. Please contact support@atlassian.com for more information.

This prevents further use of JIRA.