WSUS MMC Console Stopped working | Windows Server 2012

Issue : WSUS MMC Console stopped working suddenly.
Issue : Following error gets repeated in event viewer when user tries to open WSUS MMC console

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.

Source
System

Stack Trace:
   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
   at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.ConnectStream.WriteHeaders(Boolean async)
** this exception was nested inside of the following exception **


System.Net.WebException -- The underlying connection was closed: An unexpected error occurred on a send.

Source
Microsoft.UpdateServices.Administration

Stack Trace:
   at Microsoft.UpdateServices.Administration.AdminProxy.CreateUpdateServer(Object[] args)
   at Microsoft.UpdateServices.UI.AdminApiAccess.AdminApiTools.GetUpdateServer(String serverName, Boolean useSecureConnection, Int32 portNumber)
   at Microsoft.UpdateServices.UI.SnapIn.Scope.ServerSummaryScopeNode.ConnectToServer()
   at Microsoft.UpdateServices.UI.SnapIn.Scope.ServerSummaryScopeNode.get_ServerTools()

Solution : 

I googled for the error and thought to check the permissions of the WSUS folder where WsusContent and UpdateServicesPackages folder resides.

Strangely, my login was not having any permission.

1) I immediately granted full permission to my Account as well as to Network Service.
2) Restarted the server
3) After opening the MMC of WSUS it loaded successfully.

Hope it will work for you too.

Please revert for any query in below comments.

Thanks.