When creating a desktop group in the Management Console, the virtual desktops appear as Not Registered.

To resolve the issue, grant the logon right, Access this computer from the network to the Delivery Controller machine account(s). 

This can be modified directly on the VDA (recommended for testing):

1.To edit the policy directly on the VDA, use Local Computer Policy editor (MMC, then add the Snap-In Local Computer Policy.)

2.The policy is located in Computer Configuration -->Windows Settings -->Security Settings -->Local Policies -->User Rights Assignment

3.Locate "Access this computer from the network"

4.Click 'Add User or Group'.   Change the Object Types to include "Computers".

5.Type the names of the Delivery Controller(s).  Click 'Check Names'.  Click OK to save the change.  There will be several warnings.

Once this is determined to resolve the OU-based registration issue, policy can be applied to all the VDA's by completing one of the following tasks:

Apply a group policy from the domain controller either to the domain as a whole or to an Organizational Unit containing the Virtual Desktops for the XenDesktop farm