A common issue that can occur with users new to installing WordPress themes is a "Broken theme and/or stylesheets missing" or "The theme is missing the style.css stylesheet" error message being displayed when trying to upload or activate the theme.
Please follow the steps below to rectify this:
Download the final zip file from your downloads page.
Unzip the final zip file, you will now have the final download folder.
Do NOT upload the final download folder. Open up the final download folder.
Browse the contents and find the actual theme folder. If you look inside the theme folder, you will see a “style.css” file. This is how you know you have found the theme folder.
Using an FTP client, upload ONLY the theme folder to your “wp-content/themes” folder.
Login to your WordPress admin panel and activate the theme.
This error message does not mean that the theme you have purchased is broken, it simply means it has been uploaded it incorrectly.