XenDesktops not registering with 5.6 Feature Pack 1 [Resolved]

I had some machines on an XenDesktop 5.6 farm that were not registering. [Reviewing this again, I realize that it was actually ALL of the machines]  The first place I went to check was on in the Desktop’s registry to make sure the DDCs were correct:  HKLM\Software\\Citrix\ with HKLM\Software\Wow64\32\NodeCitrixVirtualDesktopAgentListOfDDCs
Wow64\32\Node since this particular system was a 64 bit Windows 7 box.  The registry key had both of the DDCs listed with a space between then.  Check.  Event Viewer just showed a generic message stating a failure to register with any DDCs.

Looking at my Eventlog on the actual DDC, I came across this message : 
The Citrix Broker Service failed to determine the base settings needed for the Virtual Desktop Agent of machine ‘<FDQN>’
 

The stated resolution is to check generic KB article CTX126990 but the real answer for me was in CTX129644!

I had some weird licensing issue where my license server information was corrupted/blanked out.  After following the instructions in CTX129644, all machines began registering fine.