Unable to restore ADAM/AD LDS (Active Directory Application Mode / Active Directory Lightweight Directory Services) deleted accounts. Error: An error occurred when attempting to undelete the object: The specified value already exists (4228446)

Unable to restore deleted objects in ADAM/ADLDS (Active Directory Application Mode / Active Directory Lightweight Directory Services) using the Online Restore Wizard for AD LDS. Receiving Error in the report: An error occurred when attempting to undelete the object: The specified value already exists.

Using ADSIedit connect to the Schema of the AD LDS instance. Go to the properties of CN=Object-Class and check to see if value of "searchFlags" is "1". Based on the Microsoft article https://technet.microsoft.com/en-ca/library/cc773309(v=ws.10).aspx this indicates that the attribute is set to be indexed only and not preserved in the tombstone during deletion. The default value should be "9" (8+1), which means that it will be preserved and indexed.

Change this to 9, then take a new backups and then attempt a restore. This restore should work as expected for new backups. If you need to restore a deleted object that currently exists, try the following steps:

1. Open the RMAD console and expand the Active Directory node.
2. Expand the AD LDS instance (connect to it if it does not exist).
3. Expand partitions, then your instance and then Deleted Objects.
4. Right click on the object, then go to All Tasks and then "Undelete".