Exchange 2007 ADPrep Error Executing Ldifde.exe to Import Schema File

When you are preparing an Active Directory Forest for Exchange Server 2007 installation you may encounter this error:

An error occurred when executing ‘ldifde.exe’ to import schema file ‘C:\Admin\ex2007\Setup\ServerRoles\Common\Setup\Data\PostWindows2003_schema0.ldf’. Error code: 8206. More details can be found in the error file ‘C:\Users\Administrator\AppData\Local\Temp\2\ldif.err’.

On inspection of the ldif.err file the following information is shown:

Entry DN: CN=ms-Exch-Access-Control-Map,CN=Schema,CN=Configuration,DC=exchangeserverpro,DC=netAdd error on entry starting on line 1: Busy
The server side error is: 0x21a2 The FSMO role ownership could not be verified because its directory partition has not replicated successfully with atleast one replication partner.
The extended server error is:
000021A2: SvcErr: DSID-030A0AF2, problem 5001 (BUSY), data 0

This error can occur in multi-Domain Controller environments where replication issues exist. However it can also occur in single-Domain Controller environments under some conditions due to an apparent bug in the Exchange Server 2007 SP1 and SP2 setup files.

Using the Exchange Server 2007 SP3 setup files to extend the schema should resolve the issue.