Domain Migration Administrator 7.x
E20110: Unable to load DAPI.DLL. The Exchange Administrator program must be installed to translate security on the Exchange directory.
This error occurrs because either the Microsoft Exchange 5.5 Administrator client is not installed on the DMA console machine, or the incorrect version of the Microsoft Exchange 5.5 Administrator program is installed. Exchange 5.5 Administrator can be installed from the Exchange 5.5 install files, or from Exchange 2000/2003 install files. The different source files install a different version of the file dapi.dll. DMA looks for a version 5.xxx of the dapi.dll, but Exchange 2000 RTM installs a 6.xxx version.
The resolution is to install Exchange Administrator for Exchange 5.5 by one of the methods outlined in this published Knowledge Base article:
NETIQKB1436 - What version of Exchange Administrator do I need for DMA to translate security for Exchange mailboxes?
If you have installed the Exchange 5.5 Adminsitrator from the Exchange 2000 install files, apply Exchange 2000 Service Pack 1 or later to the Exchange tools on the DMA console which will correct the DAPI.dll version.
For more informatoin please refer to the following Microsoft Knowledge Base aricle:
280136 - FIX: Incorrect Version of Dapi.dll Installed from Exchange 2000 CD for Exchange 5.5 Management Tools