In a Citrix Virtual Apps and Desktops or Xenserver\Xenapp environment, attempts to create a Machine Catalog with "pooled" desktops results in Error Id: XDDS:0F7CB924. Error Id: XDDS:0F7CB924 Exception:

Citrix.Console.Models.Exceptions.ProvisioningTaskException Create Catalog failed with an unknown reason, see terminating error for more details. at Citrix.Console.PowerShellSdk.ProvisioningSchemeService.BackgroundTasks.ProvisioningSchemeTask.CheckForTerminatingError(SdkProvisioningSchemeAction sdkProvisioningSchemeAction) at Citrix.Console.PowerShellSdk.ProvisioningSchemeService.BackgroundTasks.ProvisioningSchemeTask.WaitForProvisioningSchemeActionCompletion(Guid taskId, Action`1 actionResultsObtained) at Citrix.Console.PowerShellSdk.ProvisioningSchemeService.BackgroundTasks.ProvisioningSchemeCreationTask.StartProvisioningAction() at Citrix.Console.PowerShellSdk.ProvisioningSchemeService.BackgroundTasks.ProvisioningSchemeCreationTask.RunTask() at Citrix.Console.PowerShellSdk.BackgroundTaskService.BackgroundTask.Task.Run() DesktopStudio_ErrorId : ProvisioningTaskError ErrorCategory : NotSpecified ErrorID : FailedToReadDiskFromPreparationVm TaskErrorInformation : Terminated InternalErrorMessage : The remote server returned an error: (500) Internal Server Error. DesktopStudio_PowerShellHistory : Create Machine Catalog 

Re-install the VDA software on the master Image and ensure the machine identity service is installed.

When preparing a Single Session OS image (e.g. Windows 10), to ensure this is installed when, please use either the installer presented by the ISO when clicking autoselect.exe or the standalone installer VDAWorkstationSetup.exe on the ISO. 

Do not use the VDAWorkstationCoreSetup.exe standalone installer, as this does not contain the required machine identity service component.

For a GUI based install - at the initial "Environment" screen, the component will be installed if the  "Create a Master MCS image" option is selected.

For a command line based install, run the installer with the /mastermcsimage option
See: https://docs.citrix.com/en-us/citrix-virtual-apps-desktops-service/install-configure/install-command.html

Problem Cause