QlikView Server does not accept new sessions and / or NO SERVER message is shown on the AccessPoint

The QlikView server doesn't appear to be accepting any user sessions, and the AccessPoint may display NO SERVER.  The Management Console shows all services online, but no sessions are listed on the affected QlikView server. 

Directly connecting to the QlikView Server with the QlikView Desktop Client (Open in Server...) functions as expected, and documents can be opened.  

QlikView Server Event logs read:

300 Error StdServer: void CStdServer::DoMsgReceived (CQvMsgActiveProtocol*, CConstQvMsg): pContext->AuthenticatedUser.IsEmpty () && ServerSettings::AuthenticationLevel == 2, will throw EQ_LOCERR_FILE_CORRUPT 
20180512T074447.000-0400 20180512T080948.000-0400 4 700 Information Session stop reason: can't authenticate 

See Error StdServer: void CStdServer::DoMsgReceived for more information on this error. 

QlikView WebServer or Settings Service read:

Error System.Exception: Authentication Failed || at QlikTech.NetClient.QvClient.Open() || at QVSWrapper.QlikViewServer..ctor(Action`2 i_Logger, String i_Hostname, Int32 i_Port, Mode i_Mode, Boolean i_Https) || at QlikView.AccessPoint.QlikviewServerSetting.Connect() || at QlikView.AccessPoint.QlikviewServerSetting.Try[T](Func`2 f, Func`1 fail) || at QlikView.AccessPoint.FileScan.ScanQlikViewServerClusters(IEnumerable`1 servers, Action`2 logger, IUser user, Int32& liveQvsCount, Boolean respectBrowsable) 

The Operating System Event log may record a .NET error:
 

Unknown.  A Windows Operating System issue is currently suspected to be causing the problem, as service restarts by themselves do not resolve the problem.
Has to do with user account rights
 

Authentiaction between the QlikView Server Service (QVS) and WebServer component is failing.  A restart of the Windows host of the webserver resolved the issue. 

Added a local user account that has admin rights on the machine. Change all services to use this account.