diff --git a/dbPort/src/org/compiere/util/Env.java b/dbPort/src/org/compiere/util/Env.java
index 91151ba838..e429948061 100644
--- a/dbPort/src/org/compiere/util/Env.java
+++ b/dbPort/src/org/compiere/util/Env.java
@@ -98,12 +98,14 @@ public final class Env
 		}
 		**/
 		//bug [ 1574630 ]
-		if (!finalCall) {
-			Container c = s_windows.get(0);
-			s_windows.clear();
-			createWindowNo(c);
-		} else {
-			s_windows.clear();
+		if (s_windows.size() > 0) {
+			if (!finalCall) {
+				Container c = s_windows.get(0);
+				s_windows.clear();
+				createWindowNo(c);
+			} else {
+				s_windows.clear();
+			}
 		}
 
 		//	Clear all Context