message: Fix crash when using the "clear scene" menu
diff: @@ -1555,7 +1555,7 @@ void MainWindow::buildMainMenuEdit()
  lightsManager->clear();
  animationManager->getAnimations().clear();
  animationManager->getTimeRange() = range1f{empty};
  - animationWidget.reset();
  + animationWidget->update();
  // TODO: lights caching to avoid complete re-importing after clearing
  sg::clearAssets();
  