Fixed issue where you can't export override file is no maps_fit_param…

…eters_override.txt file exists

src/mvc/MapsElementsWidget.cpp

@@ -1138,7 +1138,15 @@ void MapsElementsWidget::on_export_fit_params(data_struct::Fit_Parameters<double
                 }
             }
         }
+        else
+        {
+            QMessageBox::critical(nullptr, "Export Fit Parameters", "Param override variable is nullptr, can't save data.");
+        }
     }
+    else
+        {
+            QMessageBox::critical(nullptr, "Export Fit Parameters", "Model is nullptr, can't save data.");
+        }
 }
 
 //---------------------------------------------------------------------------

src/mvc/MapsWorkspaceFilesWidget.cpp

@@ -266,6 +266,11 @@ void MapsWorkspaceFilesWidget::onOpenModel(const QStringList& names_list, MODEL_
                     if (param_override == nullptr)
                     {
                         param_override = _model->getParamOverride(-1);
+                    }
+                     if (param_override == nullptr)
+                    {
+                        // generate param file
+                        param_override = new data_struct::Params_Override<double>();
                     }
                     h5Model->set_fit_parameters_override(param_override);
                     emit loaded_model(name, mt);