That’s a common issue caused by not uploading the correct zip file when trying to install the theme. Go back to http://themeforest.net/downloads and when clicking the Download button, choose the “Installable WordPress file only“. This is what you should be looking for on your screen:
- Common Issues and FAQs
- How to renew support for your WordPress Themes on ThemeForest
- Error: Missing style.css
- Error: "Are you sure you want to do this? Please try again"
- Error: The link you followed has expired
- Outdated WooCommerce Templates
- WPBakery Page Builder
- How to fix Blurry Thumbs?
- Will I loose my customization if I update the theme?