diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 200ef42985..6122e74b65 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -3998,7 +3998,8 @@ void Plater::priv::set_current_panel(wxPanel* panel)
             bool model_fits = view3D->get_canvas3d()->check_volumes_outside_state() != ModelInstancePVS_Partly_Outside;
             if (!model.objects.empty() && !export_in_progress && model_fits) {
                 preview->get_canvas3d()->init_gcode_viewer();
-                preview->load_gcode_shells();
+                if (! this->background_process.finished())
+                    preview->load_gcode_shells();
                 q->reslice();
             }
             // keeps current gcode preview, if any