When attempting to open the 'Licensing' or 'Controller' sections under 'Configuration' in Citrix Studio, an error window with the following details is raised.

Error Id: XDDS:773674D1

Exception:
    DesktopStudio_ErrorId : DatabaseError
    Exception : System.NullReferenceException: 並未將物件參考設定為物件的執行個體。
       於 Citrix.Fma.Sdk.Filtering.TypeCache.<>c__DisplayClass3_0`2.<CastAndInvoke>b__0(Object t, Object o)
       於 Citrix.Fma.Sdk.Filtering.TypeCache.SetProperty(Object instance, String property, Object value)
       於 Citrix.Fma.Sdk.Filtering.SdkObjectReader.ReadSdkObject(DbDataReader db)
       於 Citrix.Fma.Sdk.Filtering.FilteringDal.GetCommonReader(Func`2 reader, Int32 maxResultCount, Object[]& sdkObjects, DbDataReader query)
       於 Citrix.Fma.Sdk.Filtering.FilteringDal.GetCommonTx(CdsTx txProvider, String query1, String query2, IEnumerable`1 sqlParameters, Func`2 reader, Nullable`1 sqlQueryTimeout, Int32 maxResultCount, Boolean returnTotalAvailableResultCount, Int32& totalAvailableResultCount, Object[]& sdkObjects)
       於 Citrix.Fma.Sdk.Filtering.FilteringDal.<>c__DisplayClass0_0.<GetCommon>b__0(CdsTx tx)
       於 Citrix.Fma.Sdk.Dal.BaseTxProvider.RunBatch(CdsTx tx, CdsTxAction txAction, String txName, Int32 retryNumber, Exception& originalException)
       於 Citrix.Fma.Sdk.Dal.BaseTxProvider.Execute(String txName, CdsTxOptions txOptions, CdsTxAction txAction, CancellationToken cancellationToken)
       於 Citrix.Fma.Sdk.Filtering.FilteringDal.GetCommon(ICdsTxProvider txProvider, String query1, String query2, IEnumerable`1 sqlParameters, Func`2 reader, Nullable`1 sqlQueryTimeout, Int32 maxResultCount, Boolean returnTotalAvailableResultCount, Int32& totalAvailableResultCount, Object[]& sdkObjects)
       於 Citrix.Fma.Sdk.Filtering.FilteringLogic.GetCommon(IQuerySchemaProvider schemaProvider, ICdsTxProvider txProvider, String operationName, IDictionary`2 arguments, String groupByProperty, ScopeList scopeIds, Nullable`1 sqlCommandTimeout, Int32 skip, Int32 maximumResultCount, Boolean returnTotalAvailableResultCount, Int32 maxDop)
       於 Citrix.Fma.Sdk.ServiceCore.CommonCmdlets.CommonCmdletsDal.CommonGetLogicDefault(String operationName, IDictionary`2 arguments, String groupByProperty, Guid[] gettableScopeIds, Int32 skip, Int32 maximumResultCount, Boolean returnTotalAvailableResultCount, Int32& totalAvailableResultCount, Object[]& records)
       於 Citrix.Fma.Sdk.ServiceCore.CommonCmdlets.CommonCmdletsDal.CommonGetLogic(String operationName, IDictionary`2 arguments, String groupByProperty, Guid[] gettableScopeIds, Int32 skip, Int32 maximumResultCount, Boolean returnTotalAvailableResultCount, Object[] extensionData, Int32& totalAvailableResultCount, Object[]& records)
    Error Source : CitrixConfigurationService
    Sdk Error Message : A database operation failed and could not be recovered : Reason 並未將物件參考設定為物件的執行個體。
    Sdk Error ID : Citrix.XDPowerShell.Status.DatabaseError,Citrix.Configuration.Sdk.Management.Commands.GetConfigServiceCommand
    ErrorCategory : NotSpecified
    DesktopStudio_PowerShellHistory : GetControllersScript
    2026/2/3 上午 11:48:47
    
    Get-BrokerController  -AdminAddress "a.b.c:80" -BearerToken ******** -MaxRecordCount 2147483647
    Get-ConfigService  -AdminAddress "a.b.c:80" -BearerToken ******** -MaxRecordCount 2147483647
    Get-ConfigService : A database operation failed and could not be recovered : Reason 並未將物件參考設定為物件的執行個體。
        + CategoryInfo : InvalidOperation: (:) [Get-ConfigService]，InvalidOperationException
        + FullyQualifiedErrorId : Citrix.XDPowerShell.Status.DatabaseError,Citrix.Configuration.Sdk.Management.Commands.GetConfigServiceCommand
    
    
    StackTrace: Citrix.Orchestration.Base.LogicModels.Exceptions.ScriptException An error occurred with the database. Contact Citrix Technical Support.
       於 Citrix.Orchestration.Base.PowerShellInteraction.CmdletExecutionMethods.CreateException[T](ExecutionResults`1 results, ICmdletExecutionHost host)
       於 Citrix.Orchestration.Base.PowerShellInteraction.CmdletExecutionMethods.Execute[T](ISdkCmdlet`1 sdkCmd, ICmdletExecutionHost host, Boolean allowFailover)
       於 Citrix.Orchestration.Base.PowerShellSdk.BrokerService.Scripts.GetControllersScript.AddZonesToModels(IList`1 controllerModels)
       於 Citrix.Orchestration.Base.PowerShellSdk.BrokerService.Scripts.GetControllersScript.RunScript()
       於 Citrix.Orchestration.Base.PowerShellInteraction.PowerShellScript`1.Run()
       於 Citrix.Orchestration.Base.PowerShellSdk.BrokerService.PSBrokerService.GetBrokers()
       於 Citrix.Console.Licensing.UI.Mmc.LicensingTabViewModel.<>c__DisplayClass39_0.<OnRefresh>b__0()
       於 Citrix.Console.CommonControls.ViewModelBase.<>c__DisplayClass90_0.<RunBackgroundTask>b__0(Object s, DoWorkEventArgs e)
    

This issue occurs after evicting a broken Delivery Controller (DDC) from the database. When checking the controller list on the remaining DDC, you may notice that a previously removed DDC with the DNSName 'a.b.c' still appears

----

ActiveSiteServices                 : {}

AssociatedHypervisorConnectionUids : {}

ControllerVersion                  : 

DNSName                            : a.b.c

DesktopsRegistered                 : 0

IsLasAware                         : False

LasActivationExpiry                : 

LasActivationStatus                : 

LasConnectionStatus                : 

LasUniqueEnvId                     : 

LastActivityTime                   : 

LastLicensingServerEvent           : 

LastLicensingServerEventDetails    : {}

LastLicensingServerEventTime       : 

LastStartTime                      : 

LicensingGracePeriodReasons        : {}

LicensingGracePeriodTimesRemaining : {}

LicensingGraceState                : NotActive

LicensingServerState               : NotConnected

MachineName                        : b.c\a

MetadataMap                        : {}

OSType                             : 

OSVersion                          : 

SID                                : 

State                              : Off

UUID                               : 

Uid                                : 

To resolve the issue, remove all records of the orphaned Delivery Controller (DDC) from the site database with the method recorded in CTX139505 - Unable to Remove XenDesktop Delivery Controllers from the XenDesktop Site.