Thanks for writing in! Please make sure you upload x.zip file. This issue usually happens when you try to upload x-package.zip file. Please unzip x-package.zip file and find and upload x.zip file to your site.
Also make sure to delete the current theme folder which you have incorrectly installed.
Thanks. I’d already figured out that was the issue. Theme Forest sent a link to a zip but I didn’t appreciate that was everything and not merely the theme until I went to my account to download again and found the choices.