This is regarding WSUS is error.we unable to fix the issue.

I have updated the WSUSCtrl.log error message.

Event Type: Error
Event Source: Windows Server Update Services
Event Category: Web Services
Event ID: 12052
Date:  9/20/2010
Time:  8:46:43 PM
User:  N/A
Computer:
Description:
The DSS Authentication Web Service is not working.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

WSUSCtrl.log

Found WSUS Admin dll of assembly version Microsoft.UpdateServices.Administration, Version=3.0.6000.273, Major Version = 0x30000, Minor Version = 0x17700111      SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM      8144 (0x1FD0)

Found WSUS Admin dll of assembly version Microsoft.UpdateServices.Administration, Version=3.1.6001.1, Major Version = 0x30001, Minor Version = 0x17710001      SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM      8144 (0x1FD0)

The installed WSUS build has the valid and supported WSUS Administration DLL assembly version (3.1.6001.1)            SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

System.Net.WebException: The request failed with HTTP status 404: Not Found.~~   at Microsoft.UpdateServices.Administration.AdminProxy.CreateUpdateServer(Object[] args)~~   at Microsoft.UpdateServices.Administration.AdminProxy.GetUpdateServer()~~   at Microsoft.SystemsManagementServer.WSUS.WSUSServer.ConnectToWSUSServer(String ServerName, Boolean UseSSL, Int32 PortNumber)    SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

STATMSG: ID=7000 SEV=E LEV=M SOURCE="SMS Server" COMP="SMS_WSUS_CONTROL_MANAGER" SYS=XXXXXXXXXXX SITE=AD1 PID=8368 TID=8144 GMTDATE=Tue Sep 21 06:32:11.322 2010 ISTR0="XXXXXXXXXXX" ISTR1="" ISTR2="" ISTR3="" ISTR4="" ISTR5="" ISTR6="" ISTR7="" ISTR8="" ISTR9="" NUMATTRS=0       SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

Failed to set WSUS Local Configuration. Will retry configuration in 1 minutes    SMS_WSUS_CONTROL_MANAGER            9/21/2010 2:32:11 AM            8144 (0x1FD0)

System.Net.WebException: The request failed with HTTP status 404: Not Found.~~   at Microsoft.UpdateServices.Administration.AdminProxy.CreateUpdateServer(Object[] args)~~   at Microsoft.UpdateServices.Administration.AdminProxy.GetUpdateServer()~~   at Microsoft.SystemsManagementServer.WSUS.WSUSServer.ConnectToWSUSServer(String ServerName, Boolean UseSSL, Int32 PortNumber)    SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

STATMSG: ID=7003 SEV=E LEV=M SOURCE="SMS Server" COMP="SMS_WSUS_CONTROL_MANAGER" SYS=XXXXXXXXXXX SITE=AD1 PID=8368 TID=8144 GMTDATE=Tue Sep 21 06:32:11.322 2010 ISTR0="XXXXXXXXXXX" ISTR1="" ISTR2="" ISTR3="" ISTR4="" ISTR5="" ISTR6="" ISTR7="" ISTR8="" ISTR9="" NUMATTRS=0       SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

Failures reported during periodic health check by the WSUS Server XXXXXXXXXXX. Will retry check in 1 minutes            SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

Waiting for changes for 1 minutes          SMS_WSUS_CONTROL_MANAGER         9/21/2010 2:32:11 AM            8144 (0x1FD0)

Kindly provide a solution to resolve the issue as soon as possible.

Hi,

Go into IIS/Web Services Extensions. In the right pane you will see all the Web Service Extensions, if you have done any updates to .NET so make sure that the status of all ASP.NET versions is "ALLOWED".

Also, take a look at these links :

http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=.NET+Framework&ProdVer=2.0.50727&EvtID=12052&EvtSrc=Windows+Server+Update+Services&LCID=1033

http://www.eventid.net/display.asp?eventid=13042&eventno=8857&source=Windows%20Server%20Update%20Services&phase=1