diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index c987dd7..a8081e4 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -1421,14 +1421,15 @@ int scanner::thread_start(void)
 	{
 		// display error message on progress UI, may be closed immediately by APP, so we hide progress UI and call message_box ...
 		// 
-		//if (callback::show_progress_ui && is_bIndicator)
-		//{
-		//	int ev = SANE_EVENT_WORKING;
-		//
-		////	on_ui_event(ev, (void*)ev);
-		//	ui_notify(SANE_EVENT_SCAN_FINISHED, (void *)hg_scanner_err_description(ret), ret);
-		//}
-		//else
+#ifdef START_SCAN_IN_THREAD
+		if (callback::show_progress_ui && is_bIndicator)
+		{
+			int ev = SANE_EVENT_WORKING;
+		
+			ui_notify(SANE_EVENT_SCAN_FINISHED, (void *)hg_scanner_err_description(ret), ret);
+		}
+		else
+#endif
 		{
 			if (callback::close_ui)
 				callback::close_ui(UI_INDICATOR);
@@ -1447,8 +1448,8 @@ int scanner::thread_start(void)
 					callback::bring_message_box_topmost(local_trans::lang_trans_between_hz936(CONST_STRING_START_FAILED).c_str());
 				MessageBoxW(app_wnd_, msg.c_str(), local_trans::lang_trans_between_hz936(CONST_STRING_START_FAILED).c_str(), MB_OK | MB_ICONERROR);
 			}
+			is_scanning_ = false;
 		}
-		is_scanning_ = false;
 	}
 	prev_start_result_ = ret;