diff --git a/UI/org.eclipse.birt.report.designer.ui.data/src/org/eclipse/birt/report/designer/data/ui/dataset/ResultSetPreviewPage.java b/UI/org.eclipse.birt.report.designer.ui.data/src/org/eclipse/birt/report/designer/data/ui/dataset/ResultSetPreviewPage.java
index 49be328dbfd..76f4eb6f8d7 100644
--- a/UI/org.eclipse.birt.report.designer.ui.data/src/org/eclipse/birt/report/designer/data/ui/dataset/ResultSetPreviewPage.java
+++ b/UI/org.eclipse.birt.report.designer.ui.data/src/org/eclipse/birt/report/designer/data/ui/dataset/ResultSetPreviewPage.java
@@ -431,8 +431,14 @@ private EngineConfig getEngineConfig( ModuleHandle handle )
 			parent = this.getClass( ).getClassLoader( );
 		}
 		ClassLoader customClassLoader = DataSetProvider.getCustomScriptClassLoader( parent, handle );
-		ec.getAppContext( ).put( EngineConstants.APPCONTEXT_CLASSLOADER_KEY,
-				customClassLoader );
+		
+//		"customerClassLoader" should not be set into engine appContext, which results in using wrong
+//		classLoader later in JavascriptEvalUtil class. Comment the following lines can make data
+//		preview work correctly.
+		
+		
+//		ec.getAppContext( ).put( EngineConstants.APPCONTEXT_CLASSLOADER_KEY,
+//				customClassLoader );
 		return ec;
 	}