The package could not be installed. The theme is missing the style.css
stylesheet.
If you've been receiving this error message when trying to install a WordPress theme, it's most likely because you're not installing the proper file. If you've purchased a WordPress zipped theme file, from a popular WordPress custom theme website, chances are you have to unzip the file partially to find the actual zipped theme file.
For example, if you've purchased a zipped WordPress theme file called 'angular' and the downloaded the theme file as angulartheme.zip you will have to unzip the file.
Once the file is unzipped, in it will be contained another file called something like 'angular.zip'. This is the file you can install using WordPress build in theme file installer uploader. You should not receive the 'The package could not be installed.' error this way.