SUP unable to Sync with upstream Server

When you configure a Software Update Point (SUP) role on a Secondary Site/Primary Site you receive an error in the WCM.log and the SUP on secondary site is not functional.  The errors are similar to the following

From the WCM.log:

  Failed to create instance of Microsoft.SystemsManagementServer.WSUS.WSUSServer. error = Unspecified error~ 

From the WSUSctrl.log:

 Failed to create instance of Microsoft.SystemsManagementServer.WSUS.WSUSServer. error = Unspecified error~

               Failed to set WSUS Local Configuration. Will retry configuration in 1 minutes

To resolve this issue re-register the wsusmsp.dll and the wsyncact.dll files.  To do this follow these steps: 

  1.       Open a CMD window and navigate to c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\.

 2.       Run the following command lines in the order listed:

 •         RegAsm.exe C:\Program Files\Microsoft Configuration Manager\bin\i386\wsyncact.dll /unregister

•         RegAsm.exe C:\Program Files\Microsoft Configuration Manager\bin\i386\wsyncact.dll

•         c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe C:\Program Files\Microsoft Configuration Manager\bin\i386\wsusmsp.dll /unregister

•         c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe C:\Program Files\Microsoft Configuration Manager\bin\i386\wsusmsp.dll

 The above commands register the Microsoft.SystemsManagementServer.SoftwareUpdatesManagement.WSyncAction.WSyncAction  class  and the Microsoft.SystemsManagementServer.WSUS.WSUSServer class successfully.

3.       Run regedit.exe and verify that the following registry keys exist:

HKEY_CLASSES_ROOT\Microsoft.SystemsManagementServer.SoftwareUpdatesManagement.WSyncAction.WSyncAction

•         HKEY_CLASSES_ROOT\CLSID\{E5272449-2083-4020-ACEE-18A145F79A75}

4.       Wait for the next Sync status to see if the sync is working now.

Note Uninstalling and reinstalling the SUP will not resolve this issue.

Source - http://support.microsoft.com/kb/962224