I have magento 2.3.1. I would like to install the theme http://demo.saharathemes.com/magento2/sahara_fashion8910/germany (sahara_fashion 10). I followed the documentation: "Next choose Content -> Design -> Configuration -> I want to install theme, select Edit Default Theme -> Applied Theme: Select layout respond to (sahara_fashion 10)" then click on save configuration, waiting with the message "please wait" and after a few minutes says "page not fond 404" and does not change the theme, see screenshot, thanks