Cannot enumerate the target exchange organization with "Cannot refresh the directory information" (4255463)

Enumeration of the target Exchange organization fails with:

Cannot refresh the directory information for DC1.Domain.com. See the Emwmigration.log file for details.

Upon examining the EMWMiration.log, the similar errors to the following may be present:

2014-04-30T14:35:52.9781030Z Thread: 0x1      Trace    Execute SQL: ADD_MAILBOX_DBCOPY @OBJECTGUID = '4975d1x4-d4b4-4dda-9221-85ae5452145d', @DN = 'CN=SERVERNAME\0ACNF:4975d1x4-d4b4-4dda-9221-85ae5452145d,CN=ITDEPT,CN=Databases,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=COMPANYNAME,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=domain,DC=com' Px414   
30/04/2014 16:35:52:978 QMMEXBasis|Quest.MigrationManager.Exchange.Basis.QSqlCommand.ExecuteNonQuery Error: Exception:

System.Data.SqlClient.SqlException: Procedure or function 'ADD_MAILBOX_DBCOPY' expects parameter '@serverdn', which was not supplied.
30/04/2014 16:35:52 aeEMWGUIShared::E2kEnumerator::Enumerate Error: -2146232060 - Procedure or function 'ADD_MAILBOX_DBCOPY' expects parameter '@SERVERDN', which was not supplied.

Migration Manager is trying to obtain information from the Configuration partition (visible in ADSIEdit) and write it to the project SQL Database. The product is unable to do so because it is unable to obtain a specific value for one of the objects it is trying to enumerate due to it being invalid or containing a value that is invalid. 

In the example shown above, it is unable to obtain the ServerDN value. This "CNF:guid" format appended to the object is created due to pre-existing object conflicts in the environment. This issue is not related to QMM but is related to pre-existing environment issues.

A Microsoft article is available elaborating on this issue at this location:

http://technet.microsoft.com/en-us/library/bb727059.aspx

It is up to the administrators of the domain in question on which path to take. In some scenarios, the objects or values referenced in the error were completely invalid and could be removed or changed appropriately after taking all precautions.

There has also been reported success of setting explicit denies on the corrupt or invalid objects for the service account directly, subsequently allowing the enumeration to return a typical access denied on those objects specifically and move onward in the enumeration process.

 These are not official recommendations, but rather examples of what had worked in the past to allow the product to succeed with enumeration.