Error creating routing number on OTMS Visual AA

[beirut]

I have an OXE rel 12.0 with 4635 voicemail, and an OTMS Rel 2.2 that was installed to move voicemail mailboxes from 4635 to OTMS.
When I delete a Z user, created previously for the 4035 voicemail, and try to add it on the Routing web interface of the Visual AA. I am getting the below error. “Could not create routing, Conflict with existing object”

I checked the User and devices on the OV8770/OTMS to make sure that user is deleted. It seems the users are still somewhere in the database. But how to remove it?