diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 5c20bac301..479b5622e1 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -5543,6 +5543,7 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
                             this->preview->update_gcode_result(partplate_list.get_current_slice_result());
                             release_PlateData_list(plate_data);
                             sidebar->obj_list()->reload_all_plates();
+                            q->suppress_background_process(true);
                         } else {
                             partplate_list.reload_all_objects();
                         }
@@ -6305,6 +6306,7 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
             if (msg.ShowModal() == wxID_YES) {}
         }
     }
+    q->schedule_background_process(true);
     return obj_idxs;
 }
 
diff --git a/src/slic3r/GUI/UnsavedChangesDialog.cpp b/src/slic3r/GUI/UnsavedChangesDialog.cpp
index 09f53d3b28..91f78f2c4b 100644
--- a/src/slic3r/GUI/UnsavedChangesDialog.cpp
+++ b/src/slic3r/GUI/UnsavedChangesDialog.cpp
@@ -1212,6 +1212,9 @@ static wxString get_string_value(std::string opt_key, const DynamicPrintConfig&
     opt_idx = orig_opt_idx >= 0 ? orig_opt_idx : 0;
     opt_key = get_pure_opt_key(opt_key);
     auto option = config.option(opt_key);
+    if (!option) {
+        return _L("N/A");
+    }
 
     if (option->is_scalar() && config.option(opt_key)->is_nil() ||
         option->is_vector() && dynamic_cast<const ConfigOptionVectorBase *>(config.option(opt_key))->is_nil(opt_idx))