Task.RunSynchronously Method (TaskScheduler)
Assemblies: System.Threading.Tasks (in System.Threading.Tasks.dll)
mscorlib (in mscorlib.dll)
The Task instance has been disposed.
The scheduler argument is null.
The Task is not in a valid state to be started. It may have already been started, executed, or canceled, or it may have been created in a manner that doesn't support direct scheduling.
Tasks executed by calling the RunSynchronously method are instantiated by calling a Task or Task<TResult> class constructor. The task to be run synchronously must be in the TaskStatus.Created state. A task may be started and run only once. Any attempts to schedule a task a second time results in an exception.
If the target scheduler does not support running this task on the current thread, the task will be scheduled for execution on the scheduler, and the current thread will block until the task has completed execution. Because of this, the calling thread does not need to call a method such as Wait to ensure that the task has completed execution.