Hello, @Taimoor Ahmad Noor,
@oshannel answer here for your request, and it’s correct 🙂 Thanks, @oshannel for your interaction on this topic…
@Taimoor Ahmad Noor Missing style sheet error when installing the theme
A common issue that can occur with users new to installing WordPress themes is a “Broken theme and/or stylesheets missing” error message being displayed when trying to upload or activate the theme. This error message does not mean that the theme you have purchased is broken, it simply means it has been uploaded incorrectly. https://help.market.envato.com/hc/en-us/articles/202821510
Regards 8Themes Team.