Call method on view to display error message

Re #27178

qt/scientific_interfaces/ISISReflectometry/GUI/MainWindow/MainWindowPresenter.cpp

@@ -200,10 +200,10 @@ void MainWindowPresenter::notifyLoadBatchRequested(int tabIndex) {
   try {
     map = MantidQt::API::loadJSONFromFile(filename);
   } catch (const std::runtime_error &e) {
-    QMessageBox::warning(
-        nullptr, QString(),
-        QString("Unable to load requested file. Please load a file of "
-                "appropriate format saved from the GUI."));
+    m_messageHandler->giveUserCritical(
+        "Unable to load requested file. Please load a file of "
+        "appropriate format saved from the GUI.",
+        "Error:");
   }
   IBatchPresenter *batchPresenter = m_batchPresenters[tabIndex].get();
   Decoder decoder;