尽管正在等待，Console.Out.WriteLine仍抛出异常

如果我在我的项目中取消注释这行代码，并注释掉它后面的一行，偶尔我会得到异常&堆栈跟踪:

System.InvalidOperationException: Operation is not valid due to the current state of the object
  at System.IO.StreamWriter.CheckState () [0x00000] in <filename unknown>:0 
  at System.IO.StreamWriter.WriteLineAsync (System.String value) [0x00000] in <filename unknown>:0 
  at System.IO.SynchronizedWriter.WriteLineAsync (System.String value) [0x00000] in <filename unknown>:0 
  at Gerty.Service+<PullJob>c__async1.MoveNext () [0x00000] in <filename unknown>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x00000] in <filename unknown>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.GetResult () [0x00000] in <filename unknown>:0 
  at Gerty.Service+<Work>c__async0.MoveNext () [0x00000] in <filename unknown>:0 

我想是什么让我困惑的是，我得到这个异常，尽管等待语句。