NullPointerException avoided

flyscan-gui/src/main/java/fr/soleil/flyscan/gui/FlyScanTangoBox.java

@@ -3286,7 +3286,14 @@ public class FlyScanTangoBox extends AbstractTangoBox {
 
         protected void treatExecutionError(Throwable error) {
             String message = TangoExceptionHelper.getErrorMessage(error);
+            if (message == null) {
+                message = ObjectUtils.EMPTY_STRING;
+            }
+            if (error == null) {
+                LOGGER.error(message);
+            } else {
                 LOGGER.error(message, error);
+            }
             displayErrorMessage(String.format(Utilities.getMessage("flyscan.configuration.read"), configName), message);
         }