The SharePoint Portal Server Single Sign On Service is Unavailable.

Microsoft.SharePointPortalServer.2003.SingleSignOnService.NTService.CheckServiceState.Monitor (UnitMonitor)

Knowledge Base article:

Summary

The SPS Single Sign On service provides single sign on services for SPS Portals. If this service is stopped, users may not be able to access SPS Portals and related resources.

Causes

A service can stop for many reasons, including:

Resolutions

The service can be restarted using the Start SPS Single Sign On Service task:

Start Single Sign On Service

If service is unable to restart successfully please refer to the tasks output which will indicate the cause for the start failure. With this information, the Services snap-in from the Computer Management console can be used to take additional resolution steps:

Start Computer Management Console

Element properties:

TargetMicrosoft.SharePointPortalServer.2003.SingleSignOnService
Parent MonitorSystem.Health.AvailabilityState
CategoryAvailabilityHealth
EnabledTrue
Alert GenerateTrue
Alert SeverityError
Alert PriorityNormal
Alert Auto ResolveTrue
Monitor TypeMicrosoft.Windows.CheckNTServiceStateMonitorType
RemotableTrue
AccessibilityPublic
Alert Message
The SharePoint Portal Server Single Sign On Service is Unavailable.
RunAsDefault

Source Code:

<UnitMonitor ID="Microsoft.SharePointPortalServer.2003.SingleSignOnService.NTService.CheckServiceState.Monitor" Target="Microsoft.SharePointPortalServer.2003.SingleSignOnService" TypeID="Windows!Microsoft.Windows.CheckNTServiceStateMonitorType" Remotable="true" Accessibility="Public" Enabled="onEssentialMonitoring" ParentMonitorID="SystemHealth!System.Health.AvailabilityState">
<Category>AvailabilityHealth</Category>
<AlertSettings AlertMessage="Microsoft.SharePointPortalServer.2003.SingleSignOnService.NTService.CheckServiceState.Monitor.AlertMessage">
<AlertOnState>Error</AlertOnState>
<AutoResolve>true</AutoResolve>
<AlertPriority>Normal</AlertPriority>
<AlertSeverity>Error</AlertSeverity>
</AlertSettings>
<OperationalStates>
<OperationalState HealthState="Success" MonitorTypeStateID="Running" ID="SingleSignOnService2003Running"/>
<OperationalState HealthState="Error" MonitorTypeStateID="NotRunning" ID="SingleSignOnService2003NotRunning"/>
</OperationalStates>
<Configuration>
<ComputerName>$Target/Host/Host/Property[Type="Windows!Microsoft.Windows.Computer"]/NetworkName$</ComputerName>
<ServiceName>SSOSRV</ServiceName>
</Configuration>
</UnitMonitor>