Citrix Error XDDS:19E984FA when creating machine catalog

When you try to create a machine catalog in Citrix XenDesktop you might get a very confusing error such as the one below.

Error Id: XDDS:19E984FA

Exception:
    Citrix.Console.Models.Exceptions.ProvisioningTaskException Failed to copy the snapshot image /DEMO-CTX01.vm/Citrix_XD_Test.snapshot to the storage referenced by the Resources DEMO-ESX51i-02.
       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 : DiskConsolidationFailed
    TaskErrorInformation : Terminated
    InternalErrorMessage : File [datastore1] DEMO-CTX01/DEMO-CTX01.vmdk was not found



I find it very difficult to troubleshoot server products that dump the entire error stack on you. It makes it impossible to read and also very difficult to Google for the solution.

In this case the problem is that the hosting resource in Citrix XenDesktop (as shown in the screenshot) is using a different datastore than is configured for the virtual machine in the vSphere client.