Queue Configuration (Service Desk/Configuration/Name of Your Queue/Customize Fields and Layout), there is an option to set the Category Default Owner. When a ticket is created, if this category is select, the ticket will be assigned to that user. In order for this user to be listed in the dropdown box for Default Owner, they must be listed in the label used for Owner Label.
However, if you remove this person from the label group, the configuration page does not know this. When you bring the page up, It simply looks at the users available from the list of the label and tries to match it to who should be listed as the Default Owner. If it cannot find a match, it will be listed as "undefined". Also, as the table still contain this users information (ID #), it Will assign the tickets to that person, even though it will not list them. The database will still list the user in its table as the Default User.
To properly remove a user from the Category, to Category Values and change either to unassigned or another user. Simply removing them from a label does not do this.
If the user has already been removed from the label and the categories are showing up as undefined, click the pencil icon to the right of that category. It will set back to Unassigned. Then click Save. Alternately, you could assign another user in the ticket owners label to the category.
Removing a user from the Ticket Owners label does not affect tickets already created. The assigned Ticket Owner will not change.
