See Use Converted Database.

After a final Conversion, clean up appointments if the previous software allowed unassigned appointments. During the final conversion, any appointments that are not assigned to an operatory, are pushed into an Unassigned or Extra operatory. These appointments must be moved into the correct operatory.

To find these appointments: In User Query Favorites, double-click the Conv - Future Appts by Operatory query.

For each appointment identified, go to the Appointments Module and move the appointment to the correct operatory.

When all appointments in the Unassigned and Extra operatories have been moved, the operatory can be removed from the Appointments Module by hiding it in Operatory Setup.

Resource: Post Conversion Checklist (PDF)