Please download the theme and Core plugin from this page – https://www.8theme.com/downloads and do the update manually https://www.8theme.com/demo/docs/legenda/Theme_Update.html https://www.8theme.com/demo/docs/legenda/Plugins/Plugins_Update
After the update, you will need to wait up to 4 hours while Woocommerce cache will be cleared and messages about outdated files disappear.
About the Cart widget, there can be another reason. Please provide temporary wp-admin and FTP access, we will check the situation more deeply.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.