diff --git a/zkwebui/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java b/zkwebui/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
index e392ebce6a..933f80e3c6 100644
--- a/zkwebui/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
+++ b/zkwebui/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
@@ -254,8 +254,11 @@ public class ProcessModalDialog extends Window implements EventListener
 	}	//	init
 
 	public void startProcess()
-	{
+	{		
 		m_pi.setPrintPreview(true);
+		if (m_ASyncProcess != null) {
+			m_ASyncProcess.lockUI(m_pi);
+		}
 		ProcessCtl.process(m_ASyncProcess, m_WindowNo, parameterPanel, m_pi, null);
 		dispose();
 	}
diff --git a/zkwebui/WEB-INF/src/org/adempiere/webui/panel/AbstractADWindowPanel.java b/zkwebui/WEB-INF/src/org/adempiere/webui/panel/AbstractADWindowPanel.java
index 3776ea20ee..685d42bc8b 100644
--- a/zkwebui/WEB-INF/src/org/adempiere/webui/panel/AbstractADWindowPanel.java
+++ b/zkwebui/WEB-INF/src/org/adempiere/webui/panel/AbstractADWindowPanel.java
@@ -1201,6 +1201,8 @@ public abstract class AbstractADWindowPanel extends AbstractUIPart implements To
 	}
 
 	public void lockUI(ProcessInfo pi) {
+		if (m_uiLocked) return;
+		
 		m_uiLocked = true;
 		boolean notPrint = pi != null 
 		&& pi.getAD_Process_ID() != curTab.getAD_Process_ID()