We had an issue where a new Active Directory user couldn’t be imported into Cisco Unity to get voicemail. I did a search and found a post that talked about a similar issue with an older version of Unity, but I thought I would give it a try.
It said to look at the properties of the AD object. So I opened ADUC, went to the properties of the account and looked at the Attribute Editor tab (you need to have Advanced Features check on the View menu). Then I looked at the properties that started with “ciscoEcsbu…”. There are 12 of these properties. Some had a value of “<not set>” while others had information in them. I edited the properties that had values and cleared whatever was there. I then had our Unity Admin try to import the AD account again. This time everything worked as expected.