This client reports it has registers successfully:

Event Type: Information
Event Source: Citrix Desktop Delivery Controller
Event Category: None
Event ID: 1222
Description:
Successfully registered with controller http://ddc.domain.com:8080/Citrix/CdsController/IRegistrar at 192.168.1.100.

The Citrix Desktop Delivery Controller comes up with the cryptic error:

Event Type: Error
Event Source: Citrix Desktop Delivery Controller
Event Category: None
Event ID: 1123
Description:
Failed to apply settings on the Virtual Desktop Agent on machine S-1-5-21-2059866640-1781623882-1245804459-27257:EE03F0293F61884D:633712191281029215. Reason:SOAP security negotiation with 'http://pvsvm.domain.com:8080/Citrix/VirtualDesktopAgent/IConfiguration' for target 'http://pvsvm.domain.com:8080/Citrix/VirtualDesktopAgent/IConfiguration' failed. See inner exception for more details..

The same issue is not seen with traditional virtual machines with a locally installed disk and a computer account created when joining the domain.

Currently, Provisioning Server creates a malformed SPN, resulting in duplicate SPN’s in all the computer accounts they have added to the domain via Provisioning Server.

To resolve this issue:

- Apply the PVS50SP1A_Hotfix8052 from CTX119911 as directed in the ReadMe.txt.
- Delete all Provisioning Server virtual machines from Active Directory.

From The Provisioning Server Console
- Select the Provisioning Server virtual machines in Device Collections.
- Right click and select Active Directory | Create Machine Account... from the context menu.
- Enter the desired OU in reverse order separated by commas e.g. XenDesktop,Desktops,Infrastructure and click OK.

From the Access Management Console on the Desktop Delivery Controller:
- Right click on the desktop group and select Properties from the context menu
- Select Virtual Desktops
- Remove all virtual machines that have had the machine account recreated above.
- Add all virtual machines that have had the machine account recreated above.
- Click OK to exit

Note: If issues occur, test adding the service account to the Hosts & Cluster with Administrator permission and removing the account from all other levels. Restart the Desktop Delivery Controller and then remove and re-add the virtual machines.

Citrix Provisioning Server 5.0 Service Pack 1a Hotfix 8052, 8006
http://support.citrix.com/article/CTX119911