Unhandled Exception: System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
   at System.Collections.ArrayList.ArrayListEnumeratorSimple.MoveNext()
   at Microsoft.PowerShell.PendingProgress.RenderHelper(ArrayList strings, ArrayList nodes, Int32 indentation, Int32 maxWidth, PSHostRawUserInterface rawUI)
   at Microsoft.PowerShell.PendingProgress.Render(Int32 maxWidth, Int32 maxHeight, PSHostRawUserInterface rawUI)
   at Microsoft.PowerShell.ProgressPane.Show(PendingProgress pendingProgress)
   at Microsoft.PowerShell.ConsoleHostUserInterface.ProgressPaneUpdateTimerElapsed(Object sender)
   at System.Threading.TimerQueueTimer.CallCallbackInContext(Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.TimerQueueTimer.CallCallback()
   at System.Threading.TimerQueueTimer.Fire()
   at System.Threading.TimerQueue.FireNextTimers()
   at System.Threading.TimerQueue.AppDomainTimerCallback()