MySQL: The description for Event ID in Source cannot be found.

If you keep getting this error in the Event Viewer you should do the following: The description for Event ID ( 100 ) in Source ( MySQL ) cannot be found It seems like the local computer may not have the necessary registry information or message DLL files to display messages from a remote

Some Client computers do not appear in the WSUS console

There are many reasons why some clients might not appear in the WSUS console. For example, GPO errors, a corrupt installation on the server or client side and issues with IIS  just to name a few. Many of these issues can be pinpointed by running the WSUS Client Diagnostic Tool