Task.WaitAll Method (Task, TimeSpan)
Waits for all of the provided Task objects to complete execution.
Assembly: mscorlib (in mscorlib.dll)
One or more of the Task objects in tasks has been disposed.
The tasks argument is null.
At least one of the Task instances was canceled -or- an exception was thrown during the execution of at least one of the Task instances. If a task was canceled, the AggregateException contains an in its InnerExceptions collection.
timeout is a negative number other than -1 milliseconds, which represents an infinite time-out -or- timeout is greater than MaxValue.
The tasks argument contains a null element.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.