In this article. Blocks the current thread until the current ManualResetEvent receives a signal, using a 32-bit signed integer to measure the time interval and specifying whether to exit the synchronization domain before the wait.. Namespace: System.Threading Assembly: mscorlib (in mscorlib.dll) Syntax 'Declaration Public Overrides Function WaitOne ( _ millisecondsTimeout As Integer the ManualResetEvent initialization is with false ManualResetEvent mre = new ManualResetEvent(false); if i understand correct, it means that it'll be block the accessing thread till the set() will be executed. what will happen if one thread will execute set(), and after it, other thread will execute WaitOne() before Reset was executed, it will Since I added the new server, the project gets stuck at the line 'waitobject.waitone' This ftpserver works a little different than the others that I'm using and I'm not sure if thats the cause of the problem. Here is the difference: I upload a zip folder which can be quite large and soon after it's uploaded, it is being moved from that ftpserver. System.AccessViolationException. Attempted to read or write protected memory. This is often an indication that other memory is corrupt. I can not figure out why this is happening. Thread 26 comes from a 3rd party library, and is back waiting by the time the crash occurs. This is a mixed native/.Net 4.6 C++ app. I'd be thankful for any help. WaitOne() will only wait until the ManualResetEvent is set, which it is very early in the threadpool thread. If you move the call to Set to the *end* of the threadpool operation, you'll see a difference. However, I predict that it won't be the difference you want. I predict it will hang. Your main UI thread is blocking until the threadpool I have the following code in my class: class MyClass. {. ManaualResetEvent myResetEvent = ManualResetEvent (false); Thread thread; // This method changes controll from one thread to another. So in theory I would like to let the. // thread asossiated with toNext excecute while blocking all other. threads.