Orchestator (robot) does not start when windows is block

Dear all,

I am starting with UIPath Orchestator. I’ve developed a process which work properly when it is started by Orchestator.
The problem is when I try to start this process while Windows is locked. It means, if I am into Windows desktop it run OK, but when I am in Credential Screen (Window is locked) process it doesnt start.

Credential was specified at the creation robot moment (domain\user & password).

P.D. we are talking about unattended robots.

I hope I could help you in a future!
Thanks in advance

It is de info, in case it could help:

Info: Se agotó el tiempo de espera.

RemoteException wrapping UiPath.Core.ElementOperationException: Se agotó el tiempo de espera. —> RemoteException wrapping System.Runtime.InteropServices.COMException: Se agotó el tiempo de espera.
en UiPath.UiNodeClass.BringIntoView()
en UiPath.Core.UiElement.BringToForeground()
— End of inner exception stack trace —
en UiPath.Core.Activities.TaskAsyncCodeActivity`1.EndExecute(AsyncCodeActivityContext context, IAsyncResult result)
en System.Activities.AsyncCodeActivity.System.Activities.IAsyncCodeActivity.FinishExecution(AsyncCodeActivityContext context, IAsyncResult result)
en System.Activities.AsyncCodeActivity.CompleteAsyncCodeActivityData.CompleteAsyncCodeActivityWorkItem.Execute(ActivityExecutor executor, BookmarkManager bookmarkManager)