Why do Entourage users see many duplicate Calendar events?

Answer

There is a bug in Entourage X and some non-updated 2004 versions which causes duplicate calendar events. The problem is that Entourage does not create calendar events with a UID (Unique IDentifier) number. These events are subseqently duplicated on the mailserver.

Fix
The easiest way to fix this is to use KMS 6.1.0 which will add a UID to any calendar events created without one.

6.1.0 has a mechanism for reparing old calendar events that are damaged. In the mailserver.cfg file located in the install directory, find the following item:

<variable name="FixCalendarUIDsOnStartup">0</variable>

Stop the mailserver, then change the '0' to a '1' as follows:

<variable name="FixCalendarUIDsOnStartup">1</variable>

When the mailserver starts up it will begin inserting UIDs into all calendar items that do not have them. This will prevent further duplication of the existing calendar items. This will only happen once. The mailserver will automatically set the FixCalendarUIDsOnStartup to 0. It is possible the mailserver will miss some users if they have never logged in. If this is the case, simply log the user in, then repeat the steps listed in this article.

More Information

If a customer persists about reparing the damage already done by this bug, there is a Apple Script created by Pavel Benes which removes the duplicate entries.

Pavel's notes are as follows:

The attached script isn't destructive (I hope) - it only marks duplicate events. This script sequentially reads each selected event and if the current event has the same subject, start time and end time as the previous event, a category Duplicated is assigned to the current event. The following steps have to be done before running this script (they could be probably included in the script too): Entourage is running select Calendar in main toolbar from main menu choose Edit – Categories – Edit Categories and create a new category with the name Duplicated (and close this dialog) in a tree Calendar Views select All Events in the right pane click on a column header Title (it sorts events by title/subject) select all messages in this view (command-A) run the script (it works slowly) now you can sort this view by category, select all events with the category Duplicated and delete them If you want to add this script to Entorage menu, copy it into folder ~/Documents/Microsoft User Data/Entourage Script Menu Items. Download the script HERE.