message: Avoid printing empty Sass error messages.
diff: @@ -521,7 +521,7 @@ async function requestThemeContents(refreshThemeTypeList: ThemeTypes.ThemeType[]
  cssFileMap.set(renderedCssFile.cssFileName, renderedCssFile.contents);
  }
  }
  - if (uiResult.errorMessage !== "") {
  + if (uiResult.errorMessage != null && uiResult.errorMessage.trim() !== "") {
  _log.warn(uiResult.errorMessage);
  }
  }
  