Chris,

On page 2-5 in the DiskXtender 6.1 Installation Guide is states:

"Note: Do not install File System Manager or MediaStor on a domain
controller. Because the creation of local groups on a domain controller is
prohibited, the installation wizard cannot create the required
DxAdministrators and DxUsers groups. In addition, Microsoft does not
support installing an application on a domain controller."

This is why you are getting the Windows error 1321: The specified user account is not a member of the specified group account.

When you connect to the DiskXtender Adminstrator, Dx needs to verify the account is in the DxAdministrators and DxUsers groups, which are created when Dx is installed. Because this is a PDC, the local groups are not created when Dx is installed, and the user credentials cannot be verified.

Hope this helps.

I understand that this is why it is happening, however we do not have the resources to get a second server to use as the DC in these sites, so this is our only option. I know it can be done, because we had it running on three of these sites until someone accidentally deleted the domain groups. I cannot seem to recall exactly how they were configured, and that's what I'm looking for help with.