If you cannot access the WSUS console and a timeout error message appears, the CPU of the WSUS server may be at, or very close to, maximum utilization, causing the database to time out. If the database software times out, the WSUS console cannot be displayed.

One way of inadvertently overtaxing your WSUS server is to have antivirus software monitor the WSUS content directory. During synchronization, the antivirus software can overload the CPU. You can work around this situation by setting the antivirus software to ignore the directory where WSUS content is stored.

If you are looking at a WSUS server on a network load balanced cluster from a remote administration console, and the server that is currently the "master" server becomes unavailable, you may see the following error:

System.Net.Sockets.SocketException Message:
No connection could be made because the target machine actively refused it
Source: System
Stack Trace:
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.InternalConnect(EndPoint remoteEP)
   at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception)

You should wait at least 30 seconds before clicking Reset on the error message.

If client computers do not appear on the Computers page in the WSUS administration console, there is probably a problem with client self-update, which is the mechanism that WSUS uses to update Automatic Update software. For more information about client self-update, see Issues with Client Self-Update.

If there are locally published updates on the server, you may not see accurate status or counts for your computer because locally published updates interfere with the filtering mechanisms.

If you want to distribute an .msc file that connects to a server, you cannot create the .msc file on that server. Instead use a console on another machine to connect to this server and then save and distribute that .msc.

If you attempt to access the WSUS administration console and fail to connect to the server, you may have gotten the following error:

The WSUS administration console was unable to connect to the WSUS Server via the remote API. 
Verify that the Update Services service, IIS, and SQL are running on the server. If the problem persists, try restarting IIS, SQL, and the Update Services Service.
The WSUS administration console has encountered an unexpected error. This may be a transient error; try restarting the administration console. If this error persists, try removing the persisted preferences for the console by deleting the wsus file under %appdata%\Microsoft\MMC\.
System.IO.IOException -- The handshake failed due to an unexpected packet format.
…

This error is probably due to the WWW Publishing service being configured to allow interaction with the desktop. To solve this problem, take the following steps:

1. Open the Services snap-in (click Start, click Run, and then type services.msc).
   
2. Right-click the World Wide Web Publishing service and select Properties.
   
3. On the LogOn tab, clear the Allow service to interact with desktop check box.
   
4. Click OK, and then dismiss the Services snap-in.
   
5. From a command shell, type iisreset.
   
6. At this point you should be able to access the WSUS server from the console again.
   

This error is caused by the issue described in KB919085 (http://go.microsoft.com/fwlink/?LinkId=86366).

In many cases, when you have gotten a connection error, it may be helpful to run the iisreset command.