Please check this before contacting us:
Many items are packaged in a master file/zip which requires unzipping to be able to access the installation file/zip for installing.
The master zip often includes other content such as documentation, additional plugins or other files. You should locate the main file for install and upload that file accordingly.
The theme is missing the style.css stylesheet error. A common issue that can occur when installing a WordPress theme is “The package could not be installed. The theme is missing the style.css stylesheet.” error message being displayed when uploading or activating the theme. You will need to extract/unzip the theme package first that you’ve downloaded.
The package inside can include ‘parent theme’, ‘child theme’, demo data and documentation.
Make sure you are uploading only the installable theme (that inside the package you download which is called theme-name.zip) through your WordPress admin section.
When you have uploaded the theme, you will need to activate the theme itself.