Visual Studio Team Services - builds have started to break after deployment
<p>We've been running an Azure VM doing CI behind Visual Studio Team Services (previously Visual Studio Online) for the longest time, and everything was working fine.</p>

<p>Very recently, almost every build has started to break, /after/ the deployment was completed and during the last "Copy binaries" step</p>

<blockquote>
  <p>Copy binaries to drop  Exception Message: The HTTP request timed out
  after 00:01:40. (type TimeoutException) Exception Stack Trace:    at
  Microsoft.TeamFoundation.Build.Workflow.Activities.FileContainerDropProvider.EndCopyDirectory(IAsyncResult
  result)    at
  Microsoft.TeamFoundation.Build.Workflow.Activities.CopyDirectory.EndExecute(AsyncCodeActivityContext
  context, IAsyncResult result)    at
  System.Activities.AsyncCodeActivity.CompleteAsyncCodeActivityData.CompleteAsyncCodeActivityWorkItem.Execute(ActivityExecutor
  executor, BookmarkManager bookmarkManager)</p>
  
  <p>Inner Exception Details:</p>
  
  <p>Exception Message: A task was canceled. (type TaskCanceledException)
  Exception Stack Trace:    at
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task
  task)    at
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task
  task)    at
  System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
  at
  Microsoft.VisualStudio.Services.Common.VssHttpMessageHandler.d__0.MoveNext()</p>
</blockquote>

<p>Any ideas as to what can be the issue?  The build server was rebooted and its drop folders cleaned up.</p>