Error "E_ADS_PROPERTY_NOT_FOUND" when using the "Extend the Active Directory Schema" tool.
* Ensure the user account specified on the "Credential and Forest" screen is a member of the Schema Admins.
* If using Windows 2000 Domain Controllers ensure that Schema Updates have been enabled
- In the Start menu, click Run and type regedt32.
- Open the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters key.
- Set the Schema Update Allowed value to 1.
Refer to Microsoft support KB "Schema Updates Require Write Access to Schema in Active Directory" for more information https://support.microsoft.com/en-us/kb/285172
* Ensure that the Schema Master Domain Controller is up and available
* Use DCDIAG to ensure replication is in a consistent state