An extended character such as a forward slash in the User Name in Active Directory can cause the LDAP query to fail. This is a Microsoft issue. If Desktop Authority version 9.2 is being used along with the latest available engine and if the script is put in extradebug mode, then more additinal information regarding the specific return code will be returned and recorded to the trace file.
The SLTrace shows the following:
Rename the user object in Active Directory and remove the forward slash or the offending character.
Note: If the forward slash is used in the Display Name field in User Properties | General Tab, this will not cause any problems.
For more information, please review the following Microsoft sites: