The newly upgraded Weibo could not be directly changed back to the original classic theme. It might be because some changes were made during the upgrade process that the classic theme no longer applies to the current version. If you want to switch back to the classic theme, you can try the following methods: 1 Uninstall the current version of Weibo and then download the classic themed version of the application. 2 If you have already installed a new version in the application, please try to upgrade to the latest version and then try to switch back to the classic theme. 3 If you get the error message "The application is not trusted", you can try to search in the app store and download the "Weibo Classic Themed" application and follow the instructions to install it. 4 If the above methods still can't solve the problem, you can try to contact the technical support team of Weibo for help. Please note that upgrading and changing applications may affect the user experience. Therefore, please make sure that you have backed up important data before upgrading.