All existing phones use Msg Centr DN of 5888. When trying to assign 5888 to the MWK of a new phone (using OTM), I get "Error: Msg Cntr DN failed validation: (MAT0054) DN must be a Msg Cntr DN. If I double-click in the Msg Cntr DN box instead of entering 5888, I get "Warning: Numbering plan is empty of not defined for this customer, or does not contain the appropriate DN type." Any thoughts?