After the Hunt List is deleted, the Hunt Group Pilot Directory Number (DN), information remains in the Cisco CallManager database. This causes problems with the dial plan and the DN cannot be reused.
The same DN shows up as an orphaned Hunt Pilot directory number when searched through the Route Plan Report in Cisco CallManager Administration.
This issue is documented in Cisco bug ID CSCsg05755, which is a duplicate of Cisco bug ID CSCsf12158. In order to resolve this issue, complete this workaround: