Blank Contact List After Upgrade to 2.6.0

I just updated from Spark 2.6.0 RC2 to 2.6.0. I am running Windows 7 SP 1. Now when I launch Spark and log in my contact list is empty and the following message is posted to the error log

Jun 7, 2011 2:35:43 PM org.jivesoftware.spark.util.log.Log error

SEVERE:

java.lang.IllegalArgumentException: illegal component position

at java.awt.Container.addImpl(Unknown Source)

at java.awt.Container.add(Unknown Source)

at org.jivesoftware.spark.ui.ContactList.addContactGroup(ContactList.java:1012)

at org.jivesoftware.spark.ui.ContactList.getUnfiledGroup(ContactList.java:2524)

at org.jivesoftware.spark.ui.ContactList.addContactGroup(ContactList.java:1070)

at org.jivesoftware.spark.ui.ContactList.buildContactList(ContactList.java:602)

at org.jivesoftware.spark.ui.ContactList.loadContactList(ContactList.java:1801)

at org.jivesoftware.spark.ui.ContactList.access$1900(ContactList.java:112)

at org.jivesoftware.spark.ui.ContactList$25$1.run(ContactList.java:1788)

at java.awt.event.InvocationEvent.dispatch(Unknown Source)

at java.awt.EventQueue.dispatchEvent(Unknown Source)

at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.run(Unknown Source)

I am not using shared groups. The only thing unusual about my groups is that I am using subgroups e.g. TopGroup::SubGroup. I don’t have any subgroups deeper than one level. Any help would be greatly appreciated.

I uninstalled it, then installed the latest 2.6.1 nightly and the contacts and groups now show.