--- OpenOpcUaCoreServer/source/VPIScheduler.cpp
+++ OpenOpcUaCoreServer/source/VPIScheduler.cpp
@@ -114,6 +114,7 @@
 	//m_pVpiDevices->clear();
 	// Scheduler variable and thread init
 	OpcUa_Semaphore_Create(&m_hStopSchedulerThread,0,0x100);
+	OpcUa_Semaphore_Create(&m_hSchedulerThreadFinished,0,1);
 	OpcUa_Semaphore_Create(&m_hVpiReaderInitialized, 0, 1);
 	OpcUa_Semaphore_Create(&m_hVpiWriterInitialized, 0, 1);
 	StartVpiReaderThread();
@@ -132,6 +133,7 @@
 	m_uiSamplingInterval=1000; // default value for the polling interval (1000)
 	m_hSchedulerThread=NULL;
 	OpcUa_Semaphore_Create(&m_hStopSchedulerThread, 0, 0x100);
+	OpcUa_Semaphore_Create(&m_hSchedulerThreadFinished,0,1);
 	OpcUa_Semaphore_Create(&m_hVpiReaderInitialized, 0, 1);
 	OpcUa_Semaphore_Create(&m_hVpiWriterInitialized, 0, 1);
 	StartVpiReaderThread();
@@ -156,6 +158,7 @@
 	//}
 	//delete m_pVpiDevices;
 	OpcUa_Semaphore_Delete(&m_hStopSchedulerThread);
+	OpcUa_Semaphore_Delete(&m_hSchedulerThreadFinished);
 	OpcUa_Semaphore_Delete(&m_hVpiReaderInitialized);
 	OpcUa_Semaphore_Delete(&m_hVpiWriterInitialized);
 	OpcUa_Mutex_Delete(&m_VpiWriteObjectsMutex);
@@ -390,14 +393,19 @@
 			}
 		}
 	}
-	OpcUa_Semaphore_Post(pVPIScheduler->m_hStopSchedulerThread,1);
+
+	OpcUa_Semaphore_Post(pVPIScheduler->m_hSchedulerThreadFinished,1);
 }
 OpcUa_StatusCode CVPIScheduler::StopVpiReaderThread()
 {
 	OpcUa_Mutex_Lock(m_VpiReaderThreadMutex);
 	m_bRunSchedulerThread=OpcUa_False;
 	OpcUa_Semaphore_Post(m_hStopSchedulerThread,1);
-	OpcUa_StatusCode uStatus = OpcUa_Semaphore_TimedWait( m_hStopSchedulerThread,OPC_TIMEOUT*2); // 15 secondes max.
+    OpcUa_Mutex_Unlock(&m_VpiReaderThreadMutex);
+
+	OpcUa_StatusCode uStatus = OpcUa_Semaphore_TimedWait( m_hSchedulerThreadFinished,OPC_TIMEOUT*2); // 15 secondes max.
+
+	OpcUa_Mutex_Lock(m_VpiReaderThreadMutex);
 	if (uStatus == OpcUa_GoodNonCriticalTimeout)
 	{
 		// on force la fin du thread de simulation